3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: Chris Wilson <[email protected]> commit 1c8c38c588ea91f8deeae21284840459d1bb58e3 upstream. This is a required workarounds for all products, especially on gen6+ where it causes the command streamer to fail to parse instructions following a WAIT_FOR_EVENT. We use WAIT_FOR_EVENT for synchronising between the GPU and the display engines, and so this bit being unset may cause hangs. References: https://bugzilla.kernel.org/show_bug.cgi?id=52311 Signed-off-by: Chris Wilson <[email protected]> Reviewed-by: Imre Deak <[email protected]> Signed-off-by: Daniel Vetter <[email protected]> [bwh: Backported to 3.2: - Adjust context - s/_MASKED_BIT/GFX_MODE/] Signed-off-by: Ben Hutchings <[email protected]> --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_ringbuffer.c | 19 +++++++++++++------ 2 files changed, 14 insertions(+), 6 deletions(-) --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -400,6 +400,7 @@ #define MI_MODE 0x0209c # define VS_TIMER_DISPATCH (1 << 6) # define MI_FLUSH_ENABLE (1 << 12) +# define ASYNC_FLIP_PERF_DISABLE (1 << 14) #define GEN6_GT_MODE 0x20d0 #define GEN6_GT_MODE_HI (1 << 9) --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -399,12 +399,20 @@ static int init_render_ring(struct intel if (INTEL_INFO(dev)->gen > 3) { int mode = VS_TIMER_DISPATCH << 16 | VS_TIMER_DISPATCH; I915_WRITE(MI_MODE, mode); - if (IS_GEN7(dev)) - I915_WRITE(GFX_MODE_GEN7, - GFX_MODE_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) | - GFX_MODE_ENABLE(GFX_REPLAY_MODE)); } + /* We need to disable the AsyncFlip performance optimisations in order + * to use MI_WAIT_FOR_EVENT within the CS. It should already be + * programmed to '1' on all products. + */ + if (INTEL_INFO(dev)->gen >= 6) + I915_WRITE(MI_MODE, GFX_MODE_ENABLE(ASYNC_FLIP_PERF_DISABLE)); + + if (IS_GEN7(dev)) + I915_WRITE(GFX_MODE_GEN7, + GFX_MODE_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) | + GFX_MODE_ENABLE(GFX_REPLAY_MODE)); + if (INTEL_INFO(dev)->gen >= 5) { ret = init_pipe_control(ring); if (ret) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
