forked from Minki/linux
e2215321ff
A race condition currently exists on Tegra, where it can happen that a monitor attached via HDMI isn't detected during the initial FB helper setup, but the hotplug event happens too early to be processed by the poll helpers because they haven't been initialized yet. This happens because on some boards the HDMI driver can control the regulator that supplies the +5V pin on the HDMI connector. Therefore depending on the timing between the initialization of the HDMI driver and the rest of DRM, it's possible that the monitor returns the hotplug signal right within the window where we would miss it. Unfortunately, drm_kms_helper_poll_init() will wreak havoc when called before at least some parts of the FB helpers have been set up. This commit fixes this by splitting out the minimum of initialization required to make drm_kms_helper_poll_init() work into a separate function that can be called early. It is then safe to move all of the poll helper initialization to an earlier point in time (before the HDMI output driver has a chance to enable the +5V supply). That way if the hotplug signal is returned before the initial FB helper setup, the monitor will be forcefully detected at that point, and if the hotplug signal is returned after that it will be properly handled by the poll helpers. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Dave Airlie <airlied@redhat.com> |
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|---|---|---|
| .. | ||
| armada | ||
| ast | ||
| bochs | ||
| bridge | ||
| cirrus | ||
| exynos | ||
| gma500 | ||
| i2c | ||
| i810 | ||
| i915 | ||
| mga | ||
| mgag200 | ||
| msm | ||
| nouveau | ||
| omapdrm | ||
| panel | ||
| qxl | ||
| r128 | ||
| radeon | ||
| rcar-du | ||
| savage | ||
| shmobile | ||
| sis | ||
| tdfx | ||
| tegra | ||
| tilcdc | ||
| 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_internal.h | ||
| drm_crtc.c | ||
| drm_debugfs.c | ||
| drm_dma.c | ||
| drm_dp_helper.c | ||
| drm_drv.c | ||
| drm_edid_load.c | ||
| drm_edid.c | ||
| drm_encoder_slave.c | ||
| drm_fb_cma_helper.c | ||
| drm_fb_helper.c | ||
| drm_flip_work.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_mipi_dsi.c | ||
| drm_mm.c | ||
| drm_modes.c | ||
| drm_modeset_lock.c | ||
| drm_panel.c | ||
| drm_pci.c | ||
| drm_plane_helper.c | ||
| drm_platform.c | ||
| drm_prime.c | ||
| drm_probe_helper.c | ||
| drm_rect.c | ||
| drm_scatter.c | ||
| drm_stub.c | ||
| drm_sysfs.c | ||
| drm_trace_points.c | ||
| drm_trace.h | ||
| drm_usb.c | ||
| drm_vm.c | ||
| drm_vma_manager.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