According to the BSpec update, bit 7 of PORT_CL1CM_DW0 register needs to be
checked to ensure that the register is in accessible state.
Also, based on a BSpec update, changing the timeout value to
check iphypwrgood, from 10ms to wait for up to 100us.

Signed-off-by: Vandana Kannan <vandana.kan...@intel.com>
Reported-by: Philippe Lecluse <philippe.lecl...@intel.com>
Cc: Deak, Imre <imre.d...@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  |  1 +
 drivers/gpu/drm/i915/intel_ddi.c | 11 +++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 7dfc400..9a02bfc 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1318,6 +1318,7 @@ enum skl_disp_power_wells {
 #define _PORT_CL1CM_DW0_A              0x162000
 #define _PORT_CL1CM_DW0_BC             0x6C000
 #define   PHY_POWER_GOOD               (1 << 16)
+#define   PHY_RESERVED                 (1 << 7)
 #define BXT_PORT_CL1CM_DW0(phy)                _BXT_PHY((phy), 
_PORT_CL1CM_DW0_BC, \
                                                        _PORT_CL1CM_DW0_A)
 
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 62de9f4..354f949 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2669,9 +2669,16 @@ static void broxton_phy_init(struct drm_i915_private 
*dev_priv,
        val |= GT_DISPLAY_POWER_ON(phy);
        I915_WRITE(BXT_P_CR_GT_DISP_PWRON, val);
 
-       /* Considering 10ms timeout until BSpec is updated */
-       if (wait_for(I915_READ(BXT_PORT_CL1CM_DW0(phy)) & PHY_POWER_GOOD, 10))
+       /*
+        * HW team confirmed that the time to reach phypowergood status is
+        * anywhere between 50 us and 100us.
+        */
+       if (wait_for_atomic_us(((!(I915_READ(BXT_PORT_CL1CM_DW0(phy)) &
+                               PHY_RESERVED)) &&
+                               ((I915_READ(BXT_PORT_CL1CM_DW0(phy)) &
+                                 PHY_POWER_GOOD) == PHY_POWER_GOOD)), 100)) {
                DRM_ERROR("timeout during PHY%d power on\n", phy);
+       }
 
        for (port =  (phy == DPIO_PHY0 ? PORT_B : PORT_A);
             port <= (phy == DPIO_PHY0 ? PORT_C : PORT_A); port++) {
-- 
1.9.1

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