Marek Szyprowski
6634117198
[ Upstream commit41a91c606e] dwc3_gadget_suspend() is called under dwc->lock spinlock. In such context calling synchronize_irq() is not allowed. Move the problematic call out of the protected block to fix the following kernel BUG during system suspend: BUG: sleeping function called from invalid context at kernel/irq/manage.c:112 in_atomic(): 1, irqs_disabled(): 128, pid: 1601, name: rtcwake 6 locks held by rtcwake/1601: #0: f70ac2a2 (sb_writers#7){.+.+}, at: vfs_write+0x130/0x16c #1: b5fe1270 (&of->mutex){+.+.}, at: kernfs_fop_write+0xc0/0x1e4 #2: 7e597705 (kn->count#60){.+.+}, at: kernfs_fop_write+0xc8/0x1e4 #3: 8b3527d0 (system_transition_mutex){+.+.}, at: pm_suspend+0xc4/0xc04 #4: fc7f1c42 (&dev->mutex){....}, at: __device_suspend+0xd8/0x74c #5: 4b36507e (&(&dwc->lock)->rlock){....}, at: dwc3_gadget_suspend+0x24/0x3c irq event stamp: 11252 hardirqs last enabled at (11251): [<c09c54a4>] _raw_spin_unlock_irqrestore+0x6c/0x74 hardirqs last disabled at (11252): [<c09c4d44>] _raw_spin_lock_irqsave+0x1c/0x5c softirqs last enabled at (9744): [<c0102564>] __do_softirq+0x3a4/0x66c softirqs last disabled at (9737): [<c0128528>] irq_exit+0x140/0x168 Preemption disabled at: [<00000000>] (null) CPU: 7 PID: 1601 Comm: rtcwake Not tainted 5.0.0-rc3-next-20190122-00039-ga3f4ee4f8a52 #5252 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c01110f0>] (unwind_backtrace) from [<c010d120>] (show_stack+0x10/0x14) [<c010d120>] (show_stack) from [<c09a4d04>] (dump_stack+0x90/0xc8) [<c09a4d04>] (dump_stack) from [<c014c700>] (___might_sleep+0x22c/0x2c8) [<c014c700>] (___might_sleep) from [<c0189d68>] (synchronize_irq+0x28/0x84) [<c0189d68>] (synchronize_irq) from [<c05cbbf8>] (dwc3_gadget_suspend+0x34/0x3c) [<c05cbbf8>] (dwc3_gadget_suspend) from [<c05bd020>] (dwc3_suspend_common+0x154/0x410) [<c05bd020>] (dwc3_suspend_common) from [<c05bd34c>] (dwc3_suspend+0x14/0x2c) [<c05bd34c>] (dwc3_suspend) from [<c051c730>] (platform_pm_suspend+0x2c/0x54) [<c051c730>] (platform_pm_suspend) from [<c05285d4>] (dpm_run_callback+0xa4/0x3dc) [<c05285d4>] (dpm_run_callback) from [<c0528a40>] (__device_suspend+0x134/0x74c) [<c0528a40>] (__device_suspend) from [<c052c508>] (dpm_suspend+0x174/0x588) [<c052c508>] (dpm_suspend) from [<c0182134>] (suspend_devices_and_enter+0xc0/0xe74) [<c0182134>] (suspend_devices_and_enter) from [<c0183658>] (pm_suspend+0x770/0xc04) [<c0183658>] (pm_suspend) from [<c0180ddc>] (state_store+0x6c/0xcc) [<c0180ddc>] (state_store) from [<c09a9a70>] (kobj_attr_store+0x14/0x20) [<c09a9a70>] (kobj_attr_store) from [<c02d6800>] (sysfs_kf_write+0x4c/0x50) [<c02d6800>] (sysfs_kf_write) from [<c02d594c>] (kernfs_fop_write+0xfc/0x1e4) [<c02d594c>] (kernfs_fop_write) from [<c02593d8>] (__vfs_write+0x2c/0x160) [<c02593d8>] (__vfs_write) from [<c0259694>] (vfs_write+0xa4/0x16c) [<c0259694>] (vfs_write) from [<c0259870>] (ksys_write+0x40/0x8c) [<c0259870>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xed55ffa8 to 0xed55fff0) ... Fixes:01c10880d2("usb: dwc3: gadget: synchronize_irq dwc irq in suspend") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("hub_wq").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.