[Intel-gfx] [PATCH 23/49] drm/i915/bxt: Increase DDI buf idle timeout

[Imre Deak]

From: Vandana Kannan <vandana.kannan at intel.com>

For BXT, DDI buf idle timeout delay needs to be increased to 16us.

Since this is a timeout value and we return as soon as the condition is
realized, no penalty incurred for other platforms.

Suggested-by: Satheeshakrishna M <satheeshakrishna.m at intel.com>
Cc: Satheeshakrishna M <satheeshakrishna.m at intel.com>
Cc: Damien Lespiau <damien.lespiau at intel.com>
Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  | 1 +
 drivers/gpu/drm/i915/intel_ddi.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index d69d7b9..60ff760 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6576,6 +6576,7 @@ enum skl_disp_power_wells {
 #define  DDI_BUF_EMP_MASK			(0xf<<24)
 #define  DDI_BUF_PORT_REVERSAL			(1<<16)
 #define  DDI_BUF_IS_IDLE			(1<<7)
+#define  DDI_BUF_IDLE_TIMEOUT			16	  /* 16us */
 #define  DDI_A_4_LANES				(1<<4)
 #define  DDI_PORT_WIDTH(width)			(((width) - 1) << 1)
 #define  DDI_INIT_DISPLAY_DETECTED		(1<<0)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 8aee7d7..a203d9d 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -322,7 +322,7 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
 	uint32_t reg = DDI_BUF_CTL(port);
 	int i;
 
-	for (i = 0; i < 8; i++) {
+	for (i = 0; i < DDI_BUF_IDLE_TIMEOUT; i++) {
 		udelay(1);
 		if (I915_READ(reg) & DDI_BUF_IS_IDLE)
 			return;
-- 
2.1.0