2632 Commits
Author SHA1 Message Date
Richard Genoud f5bb841637 tty/serial: at91: fix hardware handshake on Atmel platforms
commit 9bcffe7575 upstream.

After commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management
when hardware handshake is enabled"), the hardware handshake wasn't
functional anymore on Atmel platforms (beside SAMA5D2).

To understand why, one has to understand the flag ATMEL_US_USMODE_HWHS
first:
Before commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management
when hardware handshake is enabled"), this flag was never set.
Thus, the CTS/RTS where only handled by serial_core (and everything
worked just fine).

This commit introduced the use of the ATMEL_US_USMODE_HWHS flag,
enabling it for all boards when the user space enables flow control.

When the ATMEL_US_USMODE_HWHS is set, the Atmel USART controller
handles a part of the flow control job:
- disable the transmitter when the CTS pin gets high.
- drive the RTS pin high when the DMA buffer transfer is completed or
  PDC RX buffer full or RX FIFO is beyond threshold. (depending on the
  controller version).

NB: This feature is *not* mandatory for the flow control to work.
(Nevertheless, it's very useful if low latencies are needed.)

Now, the specifics of the ATMEL_US_USMODE_HWHS flag:

- For platforms with DMAC and no FIFOs (sam9x25, sam9x35, sama5D3,
sama5D4, sam9g15, sam9g25, sam9g35)* this feature simply doesn't work.
( source: https://lkml.org/lkml/2016/9/7/598 )
Tested it on sam9g35, the RTS pins always stays up, even when RXEN=1
or a new DMA transfer descriptor is set.
=> ATMEL_US_USMODE_HWHS must not be used for those platforms

- For platforms with a PDC (sam926{0,1,3}, sam9g10, sam9g20, sam9g45,
sam9g46)*, there's another kind of problem. Once the flag
ATMEL_US_USMODE_HWHS is set, the RTS pin can't be driven anymore via
RTSEN/RTSDIS in USART Control Register. The RTS pin can only be driven
by enabling/disabling the receiver or setting RCR=RNCR=0 in the PDC
(Receive (Next) Counter Register).
=> Doing this is beyond the scope of this patch and could add other
bugs, so the original (and working) behaviour should be set for those
platforms (meaning ATMEL_US_USMODE_HWHS flag should be unset).

- For platforms with a FIFO (sama5d2)*, the RTS pin is driven according
to the RX FIFO thresholds, and can be also driven by RTSEN/RTSDIS in
USART Control Register. No problem here.
(This was the use case of commit 1cf6e8fc83 ("tty/serial: at91: fix
RTS line management when hardware handshake is enabled"))
NB: If the CTS pin declared as a GPIO in the DTS, (for instance
cts-gpios = <&pioA PIN_PB31 GPIO_ACTIVE_LOW>), the transmitter will be
disabled.
=> ATMEL_US_USMODE_HWHS flag can be set for this platform ONLY IF the
CTS pin is not a GPIO.

So, the only case when ATMEL_US_USMODE_HWHS can be enabled is when
(atmel_use_fifo(port) &&
 !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))

Tested on all Atmel USART controller flavours:
AT91SAM9G35-CM (DMAC flavour), AT91SAM9G20-EK (PDC flavour),
SAMA5D2xplained (FIFO flavour).

* the list may not be exhaustive

Fixes: 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[nicolas.ferre@atmel.com: adapt to 4.4.x kernel for stable by adding
the atmel_port variable declaration which was missing]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-18 10:48:36 +01:00
Kefeng Wang 42c947900f serial: 8250_dw: Check the data->pclk when get apb_pclk
commit e16b46f190 upstream.

It should check the data->pclk, not data->clk when get apb_pclk.

Fixes: c8ed99d4f6a8("serial: 8250_dw: Add support for deferred probing")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-22 12:26:54 +02:00
Jimi Damon 58559c6776 serial: 8250: added acces i/o products quad and octal serial cards
commit c8d192428f upstream.

Added devices ids for acces i/o products quad and octal serial cards
that make use of existing Pericom PI7C9X7954 and PI7C9X7958
configurations .

Signed-off-by: Jimi Damon <jdamon@accesio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-24 10:07:38 +02:00
Andy Shevchenko d5d1383049 serial: 8250_mid: fix divide error bug if baud rate is 0
commit 47b34d2ef2 upstream.

Since the commit c1a67b48f6 ("serial: 8250_pci: replace switch-case by
formula for Intel MID"), the 8250 driver crashes in the byt_set_termios()
function with a divide error. This is caused by the fact that a baud rate of 0
(B0) is not handled properly. Fix it by falling back to B9600 in this case.

Reported-by: "Mendez Salinas, Fernando" <fernando.mendez.salinas@intel.com>
Fixes: c1a67b48f6 ("serial: 8250_pci: replace switch-case by formula for Intel MID")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-24 10:07:38 +02:00
Alexandre Belloni 580b1bbcc9 tty/serial: atmel: fix RS485 half duplex with DMA
commit 0058f0871e upstream.

When using DMA, half duplex doesn't work properly because rx is not stopped
before starting tx. Ensure we call atmel_stop_rx() in the DMA case.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-20 18:09:17 +02:00
Krzysztof Kozlowski 8af97d26ce serial: samsung: Fix ERR pointer dereference on deferred probe
commit e51e4d8a18 upstream.

When the clk_get() of "uart" clock returns EPROBE_DEFER, the next re-probe
finishes with success but uses invalid (ERR_PTR) values.  This leads to
dereferencing of ERR_PTR stored under ourport->clk:

	12c30000.serial: Controller clock not found
	(...)
	12c30000.serial: ttySAC3 at MMIO 0x12c30000 (irq = 61, base_baud = 0) is a S3C6400/10
	Unable to handle kernel paging request at virtual address fffffdfb

	(clk_prepare) from [<c039f7d0>] (s3c24xx_serial_pm+0x20/0x128)
	(s3c24xx_serial_pm) from [<c0395414>] (uart_change_pm+0x38/0x40)
	(uart_change_pm) from [<c039689c>] (uart_add_one_port+0x31c/0x44c)
	(uart_add_one_port) from [<c03a035c>] (s3c24xx_serial_probe+0x2a8/0x418)
	(s3c24xx_serial_probe) from [<c03ee110>] (platform_drv_probe+0x50/0xb0)
	(platform_drv_probe) from [<c03ecb44>] (driver_probe_device+0x1f4/0x2b0)
	(driver_probe_device) from [<c03eb0c0>] (bus_for_each_drv+0x44/0x8c)
	(bus_for_each_drv) from [<c03ec8c8>] (__device_attach+0x9c/0x100)
	(__device_attach) from [<c03ebf54>] (bus_probe_device+0x84/0x8c)
	(bus_probe_device) from [<c03ec388>] (deferred_probe_work_func+0x60/0x8c)
	(deferred_probe_work_func) from [<c012fee4>] (process_one_work+0x120/0x328)
	(process_one_work) from [<c0130150>] (worker_thread+0x2c/0x4ac)
	(worker_thread) from [<c0135320>] (kthread+0xd8/0xf4)
	(kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c)

The first unsuccessful clk_get() causes s3c24xx_serial_init_port() to
exit with failure but the s3c24xx_uart_port is left half-configured
(e.g. port->mapbase is set, clk contains ERR_PTR).  On next re-probe,
the function s3c24xx_serial_init_port() will exit early with success
because of configured port->mapbase and driver will use old values,
including the ERR_PTR as clock.

Fix this by cleaning the port->mapbase on error path so each re-probe
will initialize all of the port settings.

Fixes: 60e9357547 ("serial: samsung: enable clock before clearing pending interrupts during init")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-20 18:09:17 +02:00
Bjorn Andersson 79b8ddbebf tty: serial: msm: Don't read off end of tx fifo
commit 30acf549ca upstream.

For dm uarts in pio mode tx data is transferred to the fifo register 4
bytes at a time, but care is not taken when these 4 bytes spans the end
of the xmit buffer so the loop might read up to 3 bytes past the buffer
and then skip the actual data at the beginning of the buffer.

Fix this by, analogous to the DMA case, make sure the chunk doesn't
wrap the xmit buffer.

Fixes: 3a878c430f ("tty: serial: msm: Add TX DMA support")
Cc: Ivan Ivanov <iivanov.xz@gmail.com>
Reported-by: Frank Rowand <frowand.list@gmail.com>
Reported-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Andy Gross <andy.gross@linaro.org>
Tested-by: Frank Rowand <frank.rowand@am.sony.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-20 18:09:16 +02:00
Zhao Qiang 5015641d21 QE-UART: add "fsl,t1040-ucc-uart" to of_device_id
commit 11ca2b7ab4 upstream.

New bindings use "fsl,t1040-ucc-uart" as the compatible for qe-uart.
So add it.

Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07 18:14:35 -07:00
Chanwoo Choi df8ad62006 serial: samsung: Reorder the sequence of clock control when call s3c24xx_serial_set_termios()
commit b8995f527a upstream.

This patch fixes the broken serial log when changing the clock source
of uart device. Before disabling the original clock source, this patch
enables the new clock source to protect the clock off state for a split second.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-06-01 12:15:53 -07:00
Andy Shevchenko 430b4aab73 serial: 8250_mid: recognize interrupt source in handler
commit c42850f1ae upstream.

There is a special register that shows interrupt status by source. In
particular case the source can be a combination of DMA Tx, DMA Rx, and UART.

Read the register and call the handlers only for sources that request an
interrupt.

Fixes: 6ede6dcd87 ("serial: 8250_mid: add support for DMA engine handling from UART MMIO")
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01 12:15:53 -07:00
Andy Shevchenko 3c5dafe43d serial: 8250_mid: use proper bar for DNV platform
commit 107e15fc1f upstream.

Unlike Intel Medfield and Tangier platforms DNV uses PCI BAR0 for IO compatible
resources and BAR1 for MMIO. We need latter in a way to support DMA. Introduce
an additional field in the internal structure and pass PCI BAR based on device
ID.

Reported-by: "Lai, Poey Seng" <poey.seng.lai@intel.com>
Fixes: 6ede6dcd87 ("serial: 8250_mid: add support for DMA engine handling from UART MMIO")
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01 12:15:53 -07:00
David Müller 1401ebda89 serial: 8250_pci: fix divide error bug if baud rate is 0
commit 6f210c18c1 upstream.

Since commit 21947ba654 ("serial: 8250_pci: replace switch-case by
formula"), the 8250 driver crashes in the byt_set_termios() function
with a divide error. This is caused by the fact that a baud rate of 0 (B0)
is not handled properly. Fix it by falling back to B9600 in this case.

Signed-off-by: David Müller <d.mueller@elsoft.ch>
Fixes: 21947ba654 ("serial: 8250_pci: replace switch-case by formula")
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01 12:15:52 -07:00
Alexandre Belloni eb57884803 tty/serial: atmel: fix hardware handshake selection
commit 5be605ac9a upstream.

Commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when
hardware handshake is enabled") actually allowed to enable hardware
handshaking.
Before, the CRTSCTS flags was silently ignored.

As the DMA controller can't drive RTS (as explain in the commit message).
Ensure that hardware flow control stays disabled when DMA is used and FIFOs
are not available.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Fixes: 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01 12:15:52 -07:00
Geert Uytterhoeven 447ea0a34b serial: sh-sci: Remove cpufreq notifier to fix crash/deadlock
commit ff1cab374a upstream.

The BSP team noticed that there is spin/mutex lock issue on sh-sci when
CPUFREQ is used.  The issue is that the notifier function may call
mutex_lock() while the spinlock is held, which can lead to a BUG().
This may happen if CPUFREQ is changed while another CPU calls
clk_get_rate().

Taking the spinlock was added to the notifier function in commit
e552de2413 ("sh-sci: add platform device private data"), to
protect the list of serial ports against modification during traversal.
At that time the Common Clock Framework didn't exist yet, and
clk_get_rate() just returned clk->rate without taking a mutex.
Note that since commit d535a2305f ("serial: sh-sci: Require a
device per port mapping."), there's no longer a list of serial ports to
traverse, and taking the spinlock became superfluous.

To fix the issue, just remove the cpufreq notifier:
  1. The notifier doesn't work correctly: all it does is update stored
     clock rates; it does not update the divider in the hardware.
     The divider will only be updated when calling sci_set_termios().
     I believe this was broken back in 2004, when the old
     drivers/char/sh-sci.c driver (where the notifier did update the
     divider) was replaced by drivers/serial/sh-sci.c (where the
     notifier just updated port->uartclk).
     Cfr. full-history-linux commits 6f8deaef2e9675d9 ("[PATCH] sh: port
     sh-sci driver to the new API") and 3f73fe878dc9210a ("[PATCH]
     Remove old sh-sci driver").
  2. On modern SoCs, the sh-sci parent clock rate is no longer related
     to the CPU clock rate anyway, so using a cpufreq notifier is
     futile.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04 14:48:52 -07:00
Sebastian Frias fc0768092c 8250: use callbacks to access UART_DLL/UART_DLM
commit 0b41ce9910 upstream.

Some UART HW has a single register combining UART_DLL/UART_DLM
(this was probably forgotten in the change that introduced the
callbacks, commit b32b19b8ff)

Fixes: b32b19b8ff ("[SERIAL] 8250: set divisor register correctly ...")

Signed-off-by: Sebastian Frias <sf84@laposte.net>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 09:08:49 -07:00
Peter Hurley 5859b90777 serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)
commit 308bbc9ab8 upstream.

The omap-serial driver emulates RS485 delays using software timers,
but neglects to clamp the input values from the unprivileged
ioctl(TIOCSRS485). Because the software implementation busy-waits,
malicious userspace could stall the cpu for ~49 days.

Clamp the input values to < 100ms.

Fixes: 4a0ac0f55b ("OMAP: add RS485 support")
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:14 -08:00
Mika Westerberg 76e88140aa serial: 8250_pci: Add Intel Broadwell ports
commit 6c55d9b983 upstream.

Some recent (early 2015) macbooks have Intel Broadwell where LPSS UARTs are
PCI enumerated instead of ACPI. The LPSS UART block is pretty much same as
used on Intel Baytrail so we can reuse the existing Baytrail setup code.

Add both Broadwell LPSS UART ports to the list of supported devices.

Signed-off-by: Leif Liddy <leif.liddy@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:14 -08:00
Jeremy McNicoll 124efa9fd5 tty: Add support for PCIe WCH382 2S multi-IO card
commit 7dde55787b upstream.

WCH382 2S board is a PCIe card with 2 DB9 COM ports detected as
Serial controller: Device 1c00:3253 (rev 10) (prog-if 05 [16850])

Signed-off-by: Jeremy McNicoll <jmcnicol@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:14 -08:00
Linus Torvalds 682cb0cd82 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc fixes from David Miller:

 1) Finally make perf stack backtraces stable on sparc, several problems
    (mostly due to the context in which the user copies from the stack
    are done) contributed to this.

    From Rob Gardner.

 2) Export ADI capability if the cpu supports it.

 3) Hook up userfaultfd system call.

 4) When faults happen during user copies we really have to clean up and
    restore the FPU state fully.  Also from Rob Gardner

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  tty/serial: Skip 'NULL' char after console break when sysrq enabled
  sparc64: fix FP corruption in user copy functions
  sparc64: Perf should save/restore fault info
  sparc64: Ensure perf can access user stacks
  sparc64: Don't set %pil in rtrap_nmi too early
  sparc64: Add ADI capability to cpu capabilities
  tty: serial: constify sunhv_ops structs
  sparc: Hook up userfaultfd system call
2015-12-25 13:15:23 -08:00
Vijay Kumar 079317a65d tty/serial: Skip 'NULL' char after console break when sysrq enabled
When sysrq is triggered from console, serial driver for SUN hypervisor
console receives a console break and enables the sysrq. It expects a valid
sysrq char following with break. Meanwhile if driver receives 'NULL'
ASCII char then it disables sysrq and sysrq handler will never be invoked.

This fix skips calling uart sysrq handler when 'NULL' is received while
sysrq is enabled.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Acked-by: Karl Volz <karl.volz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:13:37 -05:00
Aya Mahfouz 01fd3c2744 tty: serial: constify sunhv_ops structs
Constifies sunhv_ops structures in tty's serial
driver since they are not modified after their
initialization.

Detected and found using Coccinelle.

Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:04:18 -05:00
Geert Uytterhoeven e1dd3bef6d serial: earlycon: Add missing spinlock initialization
If an earlycon console driver needs to acquire the uart_port.lock
spinlock for serial console output, and CONFIG_DEBUG_SPINLOCK=y:

    BUG: spinlock bad magic on CPU#0, swapper/0
     lock: sci_ports+0x0/0x3480, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
    CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.0-rc2-koelsch-g62ea5edf143bb1d0-dirty #2083
    Hardware name: Generic R8A7791 (Flattened Device Tree)
    [<c00173a0>] (unwind_backtrace) from [<c0013094>] (show_stack+0x10/0x14)
    [<c0013094>] (show_stack) from [<c01f2338>] (dump_stack+0x70/0x8c)
    [<c01f2338>] (dump_stack) from [<c00702d8>] (do_raw_spin_lock+0x20/0x190)
    [<c00702d8>] (do_raw_spin_lock) from [<c0267590>] (serial_console_write+0x4c/0x130)
    [<c0267590>] (serial_console_write) from [<c00734c4>] (call_console_drivers.constprop.13+0xc8/0xec)
    [<c00734c4>] (call_console_drivers.constprop.13) from [<c0074ef0>] (console_unlock+0x354/0x440)
    [<c0074ef0>] (console_unlock) from [<c0075bb4>] (register_console+0x2a0/0x394)
    [<c0075bb4>] (register_console) from [<c06cb750>] (of_setup_earlycon+0x90/0xa4)
    [<c06cb750>] (of_setup_earlycon) from [<c06cfb60>] (setup_of_earlycon+0x118/0x13c)
    [<c06cfb60>] (setup_of_earlycon) from [<c06b34ac>] (do_early_param+0x64/0xb4)
    [<c06b34ac>] (do_early_param) from [<c00472c0>] (parse_args+0x254/0x350)
    [<c00472c0>] (parse_args) from [<c06b3860>] (parse_early_options+0x2c/0x3c)
    [<c06b3860>] (parse_early_options) from [<c06b389c>] (parse_early_param+0x2c/0x40)
    [<c06b389c>] (parse_early_param) from [<c06b5b08>] (setup_arch+0x520/0xaf0)
    [<c06b5b08>] (setup_arch) from [<c06b3948>] (start_kernel+0x94/0x370)
    [<c06b3948>] (start_kernel) from [<40008090>] (0x40008090)

Initialize the spinlock in of_setup_earlycon() and register_earlycon(),
to fix this for both DT-based and legacy earlycon.  If the driver would
reinitialize the spinlock again, this is harmless, as it's allowed to
reinitialize an unlocked spinlock.

Alternatives are:
  - Drivers having an early_serial_console_write() that only performs
    the core functionality of serial_console_write(), without acquiring
    the lock (which may be unsafe, depending on the hardware),
  - Drivers initializing the spinlock in their private earlycon setup
    functions.

As uart_port is owned by generic serial_core, and uart_port.lock is
initialized by uart_add_one_port() for the normal case, this can better
be handled in the earlycon core.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Reported-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-12 23:05:28 -08:00
Yoshihiro Shimoda d09959e752 serial: sh-sci: Fix length of scatterlist
This patch fixes an issue that the "length" of scatterlist should be
set using sg_dma_len(). Otherwise, a dmaengine driver cannot work
correctly if CONFIG_NEED_SG_DMA_LENGTH=y.

Fixes: 7b39d90184 (serial: sh-sci: Fix NULL pointer dereference if HIGHMEM is enabled)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-12 21:42:31 -08:00
Masahiro Yamada 7be047e035 serial: 8250_uniphier: fix dl_read and dl_write functions
The register offset must be shifted by regshift, otherwise the
baudrate is not set.  I missed the issue probably because the
divisor register was already set by the boot loader.

Fixes: 1a8d2903cb ("serial: 8250_uniphier: add UniPhier serial driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-12 21:42:31 -08:00
Arnd Bergmann bd63acf9e9 serial: export fsl8250_handle_irq
fsl8250_handle_irq is now used by the of_serial driver, and that fails
if it is a loadable module:

ERROR: "fsl8250_handle_irq" [drivers/tty/serial/of_serial.ko] undefined!

This exports the symbol to avoid randconfig errors.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: d43b54d269 ("serial: Enable Freescale 16550 workaround on arm")
Cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20 16:19:54 -08:00
Heikki Krogerus fa70045e9d serial: 8250_mid: Add missing dependency
8250_mid uses rational_best_approximation() function, so the
driver needs to select CONFIG_RATIONAL option.

This fixes build error when CONFIG_RATIONAL is not enabled:

drivers/built-in.o: In function `mid8250_set_termios':
8250_mid.c:(.text+0x10169a): undefined reference to `rational_best_approximation'

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20 16:19:54 -08:00
Guenter Roeck f356d7a7dd serial: etraxfs-uart: Fix crash
Since commit 7d8c70d804 ("serial: mctrl-gpio: rename init function"),
crisv32 either do not build or crash as follows.

Unable to handle kernel NULL pointer dereference
Linux 4.3.0-rc7-next-20151101 #1 Sun Nov 1 11:41:28 PST 2015
...
Call Trace: [<c0004a0e>] show_stack+0x0/0x9e
[<c004c0c0>] printk+0x0/0x2c
[<c00059d4>] show_registers+0x14a/0x1c2
[<c004c0c0>] printk+0x0/0x2c
[<c0004b52>] die_if_kernel+0x7c/0x9e
[<c0005346>] do_page_fault+0x32e/0x3e6
[<c01dc59c>] of_get_property+0x0/0x2c
[<c01e0558>] of_irq_parse_raw+0x12a/0x376
[<c01dc59c>] of_get_property+0x0/0x2c
[<c0053aca>] get_page_from_freelist+0x73e/0x856
[<c01dc59c>] of_get_property+0x0/0x2c
[<c0008912>] d_mmu_refill+0x10a/0x112
[<c01b488c>] devm_kmalloc+0x40/0x56
[<c01b47d0>] add_dr+0xc/0x1c
[<c01b4800>] devm_add_action+0x2/0x4e
[<c01abdbc>] mctrl_gpio_init_noauto+0x1c/0x76
[<c01abf9e>] mctrl_gpio_init+0x22/0x110

The function call in the etraxfs-uart driver was not renamed,
possibly due to interference with commit 7b9c5162c1 ("serial:
etraxfs-uart: use mctrl_gpio helpers for handling modem signals").

Fixes: 7d8c70d804 ("serial: mctrl-gpio: rename init function")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Niklas Cassel <nks@flawful.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20 16:19:54 -08:00
Peter Hurley bec8bf61dc serial: fsl_lpuart: Fix earlycon support
Earlycon support for Freescale lpuart should only be enabled when
console support is enabled.

Fixes: 1d59b382f1 ("serial: fsl_lpuart: add earlycon support")
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20 16:19:54 -08:00
Simon Arlott 83f7fa6c29 bcm63xx_uart: Use the device name when registering an interrupt
Use the device name when registering an interrupt so that multiple
ports don't all have the same interrupt name.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20 16:19:54 -08:00
Linus Torvalds 75f5db39ff Merge tag 'spi-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi updates from Mark Brown:
 "Quite a lot of activity in SPI this cycle, almost all of it in drivers
  with a few minor improvements and tweaks in the core.

   - Updates to pxa2xx to support Intel Broxton and multiple chip selects.
   - Support for big endian in the bcm63xx driver.
   - Multiple slave support for the mt8173
   - New driver for the auxiliary SPI controller in bcm2835 SoCs.
   - Support for Layerscale SoCs in the Freescale DSPI driver"

* tag 'spi-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (87 commits)
  spi: pxa2xx: Rework self-initiated platform data creation for non-ACPI
  spi: pxa2xx: Add support for Intel Broxton
  spi: pxa2xx: Detect number of enabled Intel LPSS SPI chip select signals
  spi: pxa2xx: Add output control for multiple Intel LPSS chip selects
  spi: pxa2xx: Use LPSS prefix for defines that are Intel LPSS specific
  spi: Add DSPI support for layerscape family
  spi: ti-qspi: improve ->remove() callback
  spi/spi-xilinx: Fix race condition on last word read
  spi: Drop owner assignment from spi_drivers
  spi: Add THIS_MODULE to spi_driver in SPI core
  spi: Setup the master controller driver before setting the chipselect
  spi: dw: replace magic constant by DW_SPI_DR
  spi: mediatek: mt8173 spi multiple devices support
  spi: mediatek: handle controller_data in mtk_spi_setup
  spi: mediatek: remove mtk_spi_config
  spi: mediatek: Update document devicetree bindings to support multiple devices
  spi: fix kernel-doc warnings about missing return desc in spi.c
  spi: fix kernel-doc warnings about missing return desc in spi.h
  spi: pxa2xx: Align a few defines
  spi: pxa2xx: Save other reg_cs_ctrl bits when configuring chip select
  ...
2015-11-05 13:15:12 -08:00
Linus Torvalds f66477a0ae Merge tag 'clk-for-linus-20151104' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk updates from Stephen Boyd:
 "The majority of the changes are driver updates and new device support.
  The core framework is mostly unchanged this time around, with only a
  couple patches to expose a clk provider API and make getting clk
  parent names from DT more robust.

  Driver updates:

   - Support for clock controllers found on Broadcom Northstar SoCs and
     bcm2835 SoC

   - Support for Allwinner audio clocks

   - A few cleanup patches for Tegra drivers and support for the highest
     DFLL frequencies on Tegra124

   - Samsung exynos7 fixes and improvements

   - i.Mx SoC updates to add a few missing clocks and keep debug uart
     clocks on during kernel intialization

   - Some mediatek cleanups and support for more subsystem clocks

   - Support for msm8916 gpu/audio clocks and qcom's GDSC power domain
     controllers

   - A new driver for the Silabs si514 clock chip"

* tag 'clk-for-linus-20151104' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (143 commits)
  clk: qcom: msm8960: Fix dsi1/2 halt bits
  clk: lpc18xx-cgu: fix potential system hang when disabling unused clocks
  clk: lpc18xx-ccu: fix potential system hang when disabling unused clocks
  clk: Add clk_hw_is_enabled() for use by clk providers
  clk: Add stubs for of_clk_*() APIs when CONFIG_OF=n
  clk: versatile-icst: fix memory leak
  clk: Remove clk_{register,unregister}_multiplier()
  clk: iproc: define Broadcom NS2 iProc clock binding
  clk: iproc: define Broadcom NSP iProc clock binding
  clk: ns2: add clock support for Broadcom Northstar 2 SoC
  clk: iproc: Separate status and control variables
  clk: iproc: Split off dig_filter
  clk: iproc: Add PLL base write function
  clk: nsp: add clock support for Broadcom Northstar Plus SoC
  clk: iproc: Add PWRCTRL support
  clk: cygnus: Convert all macros to all caps
  ARM: cygnus: fix link failures when CONFIG_COMMON_CLK_IPROC is disabled
  clk: imx31: add missing of_node_put
  clk: imx27: add missing of_node_put
  clk: si5351: add missing of_node_put
  ...
2015-11-05 12:59:36 -08:00
Linus Torvalds fd0d351de7 Merge tag 'tty-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
 "Here is the big tty and serial driver update for 4.4-rc1.

  Lots of serial driver updates and a few small tty core changes.  Full
  details in the shortlog.

  All of these have been in linux-next for a while"

* tag 'tty-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (148 commits)
  tty: Use unbound workqueue for all input workers
  tty: Abstract tty buffer work
  tty: Prevent tty teardown during tty_write_message()
  tty: core: Use correct spinlock flavor in tiocspgrp()
  tty: Combine SIGTTOU/SIGTTIN handling
  serial: amba-pl011: fix incorrect integer size in pl011_fifo_to_tty()
  ttyFDC: Fix build problems due to use of module_{init,exit}
  tty: remove unneeded return statement
  serial: 8250_mid: add support for DMA engine handling from UART MMIO
  dmaengine: hsu: remove platform data
  dmaengine: hsu: introduce stubs for the exported functions
  dmaengine: hsu: make the UART driver in control of selecting this driver
  serial: fix mctrl helper functions
  serial: 8250_pci: Intel MID UART support to its own driver
  serial: fsl_lpuart: add earlycon support
  tty: disable unbind for old 74xx based serial/mpsc console port
  serial: pl011: Spelling s/clocks-names/clock-names/
  n_tty: Remove reader wakeups for TTY_BREAK/TTY_PARITY chars
  tty: synclink, fix indentation
  serial: at91, fix rs485 properties
  ...
2015-11-04 21:35:12 -08:00
Linus Torvalds 14c7909290 Merge branch 'parisc-4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:
 "The most important change is that we reduce L1_CACHE_BYTES to 16
  bytes, for which a trivial patch for XPS in the network layer was
  needed.  Then we wire up the sys_membarrier and userfaultfd syscalls
  and added two other small cleanups"

* 'parisc-4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Change L1_CACHE_BYTES to 16
  net/xps: Fix calculation of initial number of xps queues
  parisc: reduce syslog debug output
  parisc: serial/mux: Convert to uart_console_device instead of open-coded
  parisc: Wire up userfaultfd syscall
  parisc: allocate sys_membarrier system call number
2015-11-04 11:30:22 -08:00
Mark Brown 4c84518523 Merge remote-tracking branches 'spi/topic/omap-100k', 'spi/topic/omap-uwire', 'spi/topic/owner', 'spi/topic/pxa' and 'spi/topic/pxa2xx' into spi-next 2015-11-04 11:02:12 +00:00
Andrew F. Davis 3821a065f5 spi: Drop owner assignment from spi_drivers
An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-28 10:30:17 +09:00
Axel Lin aa0bdd2995 parisc: serial/mux: Convert to uart_console_device instead of open-coded
The implementation of mux_console_device() is very similar to
uart_console_device(). Setting .data field in mux_console then we can
convert to use uart_console_device().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Helge Deller <deller@gmx.de>
2015-10-22 15:44:28 +02:00
Timur Tabi 71a5cd8a4a serial: amba-pl011: fix incorrect integer size in pl011_fifo_to_tty()
The UART_DUMMY_DR_RX status bit is equal to (1 << 16), so a u16 is too small
to hold that value.  The result is that UART_DUMMY_DR_RX is never passed
to uart_insert_char().  This means that we're always accepting characters,
even when CREAD (in termios) is not set.

Signed-off-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:29:21 -07:00
Frederic Danis f967fc8f16 Revert "serial: 8250_dma: don't bother DMA with small transfers"
This reverts commit 9119fba0cf.

This commit prevents from sending "big" file using Bluetooth.
When sending a lot of data quickly through the Bluetooth interface, and
after a variable amount of data sent, transfer fails with error:
    kernel: [  415.247453] Bluetooth: hci0 hardware error 0x00

Found on T100TA.

After reverting this commit, send works fine for any file size.

Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Fixes: 9119fba0cf (serial: 8250_dma: don't bother DMA with small transfers)
Cc: stable@vger.kernel.org
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:24:46 -07:00
Heikki Krogerus 6ede6dcd87 serial: 8250_mid: add support for DMA engine handling from UART MMIO
The platforms that have this UART, but that don't have
separate PCI device for the DMA Engine, need to create the
HSU DMA Engine device separately.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:22:08 -07:00
Heikki Krogerus ec2f1b67f5 dmaengine: hsu: make the UART driver in control of selecting this driver
HSU (High Speed UART) DMA engine, like the name suggests, is
an integrated DMA engine for UART and UART alone. Therefore,
making the UART drivers responsible of selecting it and
removing the user selectable option for it. The UARTs with
this DMA engine can always select HSU_DMA when
SERIAL_8250_DMA option is enabled.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:22:08 -07:00
Arnd Bergmann 1b306f997e serial: fix mctrl helper functions
A recent patch to create common helper functions for modem control
lines created empty helper functions in a header file, but accidentally
did not mark them as 'static inline', which causes build errors:

drivers/tty/serial/mxs-auart.o: In function `mctrl_gpio_enable_ms':
mxs-auart.c:(.text+0x171c): multiple definition of `mctrl_gpio_enable_ms'
drivers/tty/serial/clps711x.o:clps711x.c:(.text+0x768): first defined here
drivers/tty/serial/mxs-auart.o: In function `mctrl_gpio_disable_ms':
mxs-auart.c:(.text+0x1720): multiple definition of `mctrl_gpio_disable_ms'
drivers/tty/serial/clps711x.o:clps711x.c:(.text+0x76c): first defined here

This adds the missing annotation, so the functions do not get placed
in each object file.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: ce59e48fdb ("serial: mctrl_gpio: implement interrupt handling")
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:21:07 -07:00
Heikki Krogerus d9eda9bab2 serial: 8250_pci: Intel MID UART support to its own driver
Intel MID UART quirks require already quite a bit of code
in 8250_pci.c. On new Intel platforms where it is used, the
integrated DMA engine no longer has its own PCI device, but
is instead configured from the UART's MMIO. That means we
will have to add even more code for handling just MID UARTs.

Instead of adding that to 8250_pci.c, splitting the support
of Intel MID UART into its own driver. Handling of the
integrated DMA engine becomes much simpler this way. Own
driver will also remove the need for things like specific
set_termios hooks for every board using this UART, and
simplify the handling of it in general.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:18:38 -07:00
Stefan Agner 1d59b382f1 serial: fsl_lpuart: add earlycon support
Add support for DT and command line based earlycon support for
lpuart and lpuart32 used on Freescale Vybrid and and QorIQ LS1021A
processors.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:18:30 -07:00
Paul Gortmaker 6200cbaf62 tty: disable unbind for old 74xx based serial/mpsc console port
We recently got rid of some modular code in this driver and also
got rid of the unused ".remove" function at the same time.  Thierry
noted that it was however possible to force the remove through the
bind/unbind interface.

Since this is a console device used on 2005 vintage 74xx based
powerpc embedded targets, and is essentially always used in
conjunction with SERIAL_MPSC_CONSOLE=y -- there is no sane reason
anyone would ever want to unbind the builtin driver and lose the
console.  So we just explicitly block bind/unbind operations and
prevent root from shooting themselves in the foot.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-serial@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:18:30 -07:00
Jiri Slaby 77bdec6f0f serial: at91, fix rs485 properties
There is a misplaced bracket in atmel_init_rs485 which sets
rs485-rx-during-tx and rs485-enabled-at-boot-time only if
rs485-rts-delay is set in of.

This is clearly a bug, so fix it by moving the bracket to the proper
place.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:14:06 -07:00
Peter Hurley cc2aaabfd6 tty: Remove tty_port::close_wait
With the removal of tty_wait_until_sent_from_close(), tty drivers
no longer wait during open for parallel closes to complete (instead,
the tty core waits before calling the driver open() method). Thus,
the close_wait waitqueue is no longer used for waiting.

Remove struct tty_port::close_wait.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:11:29 -07:00
Peter Hurley fef062cbf2 tty: Remove ASYNC_CLOSING checks in open()/hangup() methods
Since at least before 2.6.30, tty drivers that do not drop the tty lock
while closing cannot observe ASYNC_CLOSING set while holding the
tty lock; this includes the tty driver's open() and hangup() methods,
since the tty core calls these methods holding the tty lock.

For these drivers, waiting for ASYNC_CLOSING to clear while opening
is not required, since this condition cannot occur. Similarly, even
when the open() method drops and reacquires the tty lock after
blocking, ASYNC_CLOSING cannot be set (again, for drivers that
do not drop the tty lock while closing).

Now that tty port drivers no longer drop the tty lock while closing
(since 'tty: Remove tty_wait_until_sent_from_close()'), the same
conditions apply: waiting for ASYNC_CLOSING to clear while opening
is not required, nor is re-checking ASYNC_CLOSING after dropping and
reacquiring the tty lock while blocking (eg., in *_block_til_ready()).

Note: The ASYNC_CLOSING flag state is still maintained since several
bitrotting drivers use it for (dubious) other purposes.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:11:29 -07:00
Jon Hunter 32ede4a517 serial: tegra: Add helper function for handling RX buffer
In the tegra UART driver there are three places where the RX DMA buffer
is handled and pushed up to the tty layer. In all three instances the
same functions are called and so instead of duplicating the code in three
places, move this code to a new helper function and use this new function.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:07:57 -07:00
Jon Hunter b0e066ccb5 serial: tegra: Remove redundant code and check in tegra_uart_stop_rx()
The serial-tegra driver always uses DMA and hence the driver always
allocates DMA channels. Therefore, the test to see if the RX DMA channel
is initialised in tegra_uart_stop_rx() is unnecessary and so remove
the test and the code that corresponds to the case where the RX DMA
channel is not initialised. Please note that the call to
tegra_uart_stop_rx() should always be before the call to
tegra_uart_shutdown() which will uninitialise the RX DMA channel.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:07:57 -07:00
Jon Hunter 2230a9475f serial: tegra: Remove unnecessary return statements
Some functions in the serial-tegra driver have unnecessary return
statements at the end of a void function and so remove them.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:07:57 -07:00