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drm/i915: BXT DDI PHY sequence BUN

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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.

v2: [Ville] use wait_for_us instead of the atomic call.
v3: [Jani/Imre] read register only once

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
Reported-by: Philippe Lecluse <Philippe.Lecluse@intel.com>
Cc: Deak, Imre <imre.deak@intel.com>
Cc: Nikula, Jani <jani.nikula@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459446354-19012-1-git-send-email-vandana.kannan@intel.com
This commit is contained in:
Vandana Kannan 2016-03-31 23:15:54 +05:30 committed by Imre Deak
parent 39ff747b2f
commit b61e79967a
2 changed files with 12 additions and 2 deletions
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1
drivers/gpu/drm/i915/i915_reg.h
View file

@ -1324,6 +1324,7 @@ 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)

13
drivers/gpu/drm/i915/intel_ddi.c
View file

@ -1732,9 +1732,18 @@ 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))
/*
* The PHY registers start out inaccessible and respond to reads with
* all 1s. Eventually they become accessible as they power up, then
* the reserved bit will give the default 0. Poll on the reserved bit
* becoming 0 to find when the PHY is accessible.
* HW team confirmed that the time to reach phypowergood status is
* anywhere between 50 us and 100us.
*/
if (wait_for_us(((I915_READ(BXT_PORT_CL1CM_DW0(phy)) &
(PHY_RESERVED | 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++) {