drm/i915: avoid premature DP AUX timeouts
During DP AUX communication we might time out 1 jiffy too early, because
the calculated expiry jiffy value is one less than needed.
This is only one reason for false DP AUX timeouts. For a complete
solution we also need the following fix, which is now queued for
mainline: http://marc.info/?l=linux-kernel&m=136748515710837&w=2
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=64133
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index 98cd8535..639fe19 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -263,7 +263,8 @@
/* Important: The hw handles only the first bit, so set only one! */
I915_WRITE(GMBUS4 + reg_offset, GMBUS_IDLE_EN);
- ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C, 10);
+ ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
+ msecs_to_jiffies_timeout(10));
I915_WRITE(GMBUS4 + reg_offset, 0);