b0a2658acb
This piece of neat lore has been ported painstakingly and bug-for-bug compatible from the old crtc helper code. Imo it's utter nonsense. If you disconnected a cable and before you reconnect it, userspace (or the kernel) does an set_crtc call, this will result in that connector getting disabled. Which will result in a nice black screen when plugging in the cable again. There's absolutely no reason the kernel does such policy enforcements - if userspace tries to set up a mode on something disconnected we might fail loudly (since the dp link training fails), but silently adjusting the output configuration behind userspace's back is a recipe for disaster. Specifically I think that this could explain some of our MI_WAIT hangs around suspend, where userspace issues a scanline wait on a disable pipe. This mechanisims here could explain how that pipe got disabled without userspace noticing. Note that this fixes a NULL deref at BIOS takeover when the firmware sets up a disconnected output in a clone configuration with a connected output on the 2nd pipe: When doing the full modeset we don't have a mode for the 2nd pipe and OOPS. On the first pipe this doesn't matter, since at boot-up the fbdev helpers will set up the choosen configuration on that on first. Since this is now the umptenth bug around handling this imo brain-dead semantics correctly, I think it's time to kill it and see whether there's any userspace out there which relies on this. It also nicely demonstrates that we have a tiny window where DP hotplug can still kill the driver. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=58396 Cc: stable@vger.kernel.org Tested-by: Peter Ujfalusi <peter.ujfalusi@gmail.com> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
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.. | ||
dvo.h | ||
dvo_ch7xxx.c | ||
dvo_ch7017.c | ||
dvo_ivch.c | ||
dvo_ns2501.c | ||
dvo_sil164.c | ||
dvo_tfp410.c | ||
i915_debugfs.c | ||
i915_dma.c | ||
i915_drv.c | ||
i915_drv.h | ||
i915_gem.c | ||
i915_gem_context.c | ||
i915_gem_debug.c | ||
i915_gem_dmabuf.c | ||
i915_gem_evict.c | ||
i915_gem_execbuffer.c | ||
i915_gem_gtt.c | ||
i915_gem_stolen.c | ||
i915_gem_tiling.c | ||
i915_ioc32.c | ||
i915_irq.c | ||
i915_reg.h | ||
i915_suspend.c | ||
i915_sysfs.c | ||
i915_trace.h | ||
i915_trace_points.c | ||
intel_acpi.c | ||
intel_bios.c | ||
intel_bios.h | ||
intel_crt.c | ||
intel_ddi.c | ||
intel_display.c | ||
intel_dp.c | ||
intel_drv.h | ||
intel_dvo.c | ||
intel_fb.c | ||
intel_hdmi.c | ||
intel_i2c.c | ||
intel_lvds.c | ||
intel_modes.c | ||
intel_opregion.c | ||
intel_overlay.c | ||
intel_panel.c | ||
intel_pm.c | ||
intel_ringbuffer.c | ||
intel_ringbuffer.h | ||
intel_sdvo.c | ||
intel_sdvo_regs.h | ||
intel_sprite.c | ||
intel_tv.c | ||
Makefile |