adf00b26d1
... even if the actual infoframe is smaller than the maximum possible size. If we don't write all the 32 DIP data bytes the InfoFrame ECC may not be correctly calculated in some cases (e.g., when changing the port), and this will lead to black screens on HDMI monitors. The ECC value is generated by the hardware. I don't see how this should break anything since we're writing 0 and that should be the correct value, so this patch should be safe. Notice that on IVB and older we actually have 64 bytes available for VIDEO_DIP_DATA, but only bytes 0-31 actually store infoframe data: the others are either read-only ECC values or marked as "reserved". On HSW we only have 32 bytes, and the ECC value is stored on its own separate read-only register. See BSpec. This patch fixes bug #46761, which is marked as a regression introduced by commit 4e89ee174bb2da341bf90a84321c7008a3c9210d: drm/i915: set the DIP port on ibx_write_infoframe Before commit 4e89 we were just failing to send AVI infoframes when we needed to change the port, which can lead to black screens in some cases. After commit 4e89 we started sending infoframes, but with a possibly wrong ECC value. After this patch I hope we start sending correct infoframes. Version 2: - Improve commit message - Try to make the code more clear Cc: stable@vger.kernel.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=46761 Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
||
|---|---|---|
| .. | ||
| ast | ||
| cirrus | ||
| exynos | ||
| gma500 | ||
| i2c | ||
| i810 | ||
| i915 | ||
| mga | ||
| mgag200 | ||
| nouveau | ||
| r128 | ||
| radeon | ||
| savage | ||
| shmobile | ||
| sis | ||
| tdfx | ||
| ttm | ||
| udl | ||
| via | ||
| vmwgfx | ||
| ati_pcigart.c | ||
| drm_agpsupport.c | ||
| drm_auth.c | ||
| drm_buffer.c | ||
| drm_bufs.c | ||
| drm_cache.c | ||
| drm_context.c | ||
| drm_crtc_helper.c | ||
| drm_crtc.c | ||
| drm_debugfs.c | ||
| drm_dma.c | ||
| drm_dp_i2c_helper.c | ||
| drm_drv.c | ||
| drm_edid_load.c | ||
| drm_edid_modes.h | ||
| drm_edid.c | ||
| drm_encoder_slave.c | ||
| drm_fb_cma_helper.c | ||
| drm_fb_helper.c | ||
| drm_fops.c | ||
| drm_gem_cma_helper.c | ||
| drm_gem.c | ||
| drm_global.c | ||
| drm_hashtab.c | ||
| drm_info.c | ||
| drm_ioc32.c | ||
| drm_ioctl.c | ||
| drm_irq.c | ||
| drm_lock.c | ||
| drm_memory.c | ||
| drm_mm.c | ||
| drm_modes.c | ||
| drm_pci.c | ||
| drm_platform.c | ||
| drm_prime.c | ||
| drm_proc.c | ||
| drm_scatter.c | ||
| drm_stub.c | ||
| drm_sysfs.c | ||
| drm_trace_points.c | ||
| drm_trace.h | ||
| drm_usb.c | ||
| drm_vm.c | ||
| Kconfig | ||
| Makefile | ||
| README.drm | ||
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html