[PATCH] drm/i915/bdw: Increase IPS disable timeout to 100ms

Imre Deak
2018-09-05T10:00:05Z

During IPS disabling the current 42ms timeout value leads to occasional
timeouts, increase it to 100ms which seems to get rid of the problem.

References: https://bugs.freedesktop.org/show_bug.cgi?id=107494
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107562
Reported-by: Diego Viola <diego.viola@gmail.com>
Tested-by: Diego Viola <diego.viola@gmail.com>
Cc: Diego Viola <diego.viola@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a85a83f31979..1bd14c61dab5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5082,10 +5082,14 @@ void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
mutex_lock(&dev_priv->pcu_lock);
WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0));
mutex_unlock(&dev_priv->pcu_lock);
- /* wait for pcode to finish disabling IPS, which may take up to 42ms */
+ /*
+ * Wait for PCODE to finish disabling IPS. The BSpec specified
+ * 42ms timeout value leads to occasional timeouts so use 100ms
+ * instead.
+ */
if (intel_wait_for_register(dev_priv,
IPS_CTL, IPS_ENABLE, 0,
- 42))
+ 100))
DRM_ERROR("Timed out waiting for IPS disable\n");
} else {
I915_WRITE(IPS_CTL, 0);
--
2.13.2