FBC disable on 965 can take long enough to trigger latency checks in the kernel so be sure to timeout after a reasonable period.
Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15015. Tested-by: James Ettle <theholyet...@googlemail.com> Signed-off-by: Jesse Barnes <jbar...@virtuousgeek.org> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 06761e4..88d52a3 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -927,19 +927,28 @@ static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval) void i8xx_disable_fbc(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; + unsigned long timeout = jiffies + msecs_to_jiffies(1); u32 fbc_ctl; if (!I915_HAS_FBC(dev)) return; + if (!(I915_READ(FBC_CONTROL) & FBC_CTL_EN)) + return; /* Already off, just return */ + /* Disable compression */ fbc_ctl = I915_READ(FBC_CONTROL); fbc_ctl &= ~FBC_CTL_EN; I915_WRITE(FBC_CONTROL, fbc_ctl); /* Wait for compressing bit to clear */ - while (I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING) - ; /* nothing */ + while (I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING) { + if (time_after(jiffies, timeout)) { + DRM_DEBUG_DRIVER("FBC idle timed out\n"); + break; + } + ; /* do nothing */ + } intel_wait_for_vblank(dev); _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
