On Friday 08 May 2015 06:49 PM, Ville Syrjälä wrote:
On Fri, May 08, 2015 at 06:24:42PM +0530, Deepak S wrote:On Friday 10 April 2015 08:51 PM, ville.syrj...@linux.intel.com wrote:From: Ville Syrjälä <ville.syrj...@linux.intel.com> Sometimes (exactly when is a bit unclear) DISPLAY_PHY_CONTROL appears to get corrupted. The values I've managed to read from it seem to have some pattern but vary quite a lot. The corruption doesn't seem to just happen when the register is accessed, but can also happen spontaneosly during modeset. When this happens during a modeset things go south and the display doesn't light up. I've managed to hit the problemn when toggling HDMI on port D on and off. When things get corrupted the display doesn't light up, but as soon as I manually write the correct value to the register the display comes up. First I was suspicious that we ourselves accidentally overwrite it with garbage, but didn't catch anything with the reg_rw tracepoint. Also I sprinkled check all over the modeset path to see exactly when the corruption happens, and eg. the read back value was fine just before intel_dp_set_m(), and corrupted immediately after it. I also made my check function repair the register value whenever it was wrong, and with this approach the corruption repeated several times during the modeset operation, always seeming to trigger in the same exact calls to the check function, while other calls to the function never caught anything. So far I've not seen this problem occurring when carefully avoiding all read accesses to DISPLAY_PHY_CONTROL. Not sure if that's just pure luck or an actual workaround, but we can hope it works. So let's avoid reading the register and instead track the desired value of the register in dev_priv. v2: Read out the power well state to determine initial register value v3: Use DPIO_CHx names instead of raw numbersEven reading once DISPLAY_PHY_CONTROL layer is getting corrupted?Not always. I think it somehow depends on what other register accesses happen around it. So there is perhaps some magic sequence that might allow reading it, but I decided that it's better to be safe and never read it.I saw similar issues on my setup. On some platform access phy is causing system behave inconsistently :(Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com> --- drivers/gpu/drm/i915/i915_drv.h | 2 ++ drivers/gpu/drm/i915/i915_reg.h | 5 ++++- drivers/gpu/drm/i915/intel_runtime_pm.c | 36 ++++++++++++++++++++++++++++----- 3 files changed, 37 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 822f259..288c3fc 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1754,6 +1754,8 @@ struct drm_i915_private {u32 fdi_rx_config; + u32 chv_phy_control;+ u32 suspend_count; struct i915_suspend_saved_registers regfile; struct vlv_s0ix_state vlv_s0ix_state; diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index cfbd5a6..98588d5 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -1887,7 +1887,10 @@ enum skl_disp_power_wells { #define DPIO_PHY_STATUS (VLV_DISPLAY_BASE + 0x6240) #define DPLL_PORTD_READY_MASK (0xf) #define DISPLAY_PHY_CONTROL (VLV_DISPLAY_BASE + 0x60100) -#define PHY_COM_LANE_RESET_DEASSERT(phy) (1 << (phy)) +#define PHY_CH_SU_PSR 0x1 +#define PHY_CH_DEEP_PSR 0x7PHY_CH_DEEP_PSR defined but not used in this patch?Just wanted to define it since it's the only other valid value, and the doc situation is crap. I've not played around with PSR so I'm not entirely sure how these would be used in practise. My gut is telling me SU_PSR might be used with link standby and DEEP_PSR with link off, but that's just a hunch at this point.
right ville, DEEP_PSR is related to link off. I will try to find the docs related to this.
You'll see in later patches that we'll start using the override bits to force the power state, so I think at that point these don't even matter. But I suppose when we enter PSR we should drop the override bits to allow the hardware to manage the power states based on the PSR mode selected.other than this, patch does what it says. Reviewed-by: Deepak S<deepa...@linux.intel.com>+#define PHY_CH_POWER_MODE(mode, phy, ch) ((mode) << (6*(phy)+3*(ch)+2)) +#define PHY_COM_LANE_RESET_DEASSERT(phy) (1 << (phy)) #define DISPLAY_PHY_STATUS (VLV_DISPLAY_BASE + 0x60104) #define PHY_POWERGOOD(phy) (((phy) == DPIO_PHY0) ? (1<<31) : (1<<30))diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.cindex ce00e69..b73671f 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -666,8 +666,8 @@ static void chv_dpio_cmn_power_well_enable(struct drm_i915_private *dev_priv, if (wait_for(I915_READ(DISPLAY_PHY_STATUS) & PHY_POWERGOOD(phy), 1)) DRM_ERROR("Display PHY %d is not power up\n", phy);- I915_WRITE(DISPLAY_PHY_CONTROL, I915_READ(DISPLAY_PHY_CONTROL) |- PHY_COM_LANE_RESET_DEASSERT(phy)); + dev_priv->chv_phy_control |= PHY_COM_LANE_RESET_DEASSERT(phy); + I915_WRITE(DISPLAY_PHY_CONTROL, dev_priv->chv_phy_control); }static void chv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,@@ -687,8 +687,8 @@ static void chv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv, assert_pll_disabled(dev_priv, PIPE_C); }- I915_WRITE(DISPLAY_PHY_CONTROL, I915_READ(DISPLAY_PHY_CONTROL) &- ~PHY_COM_LANE_RESET_DEASSERT(phy)); + dev_priv->chv_phy_control &= ~PHY_COM_LANE_RESET_DEASSERT(phy); + I915_WRITE(DISPLAY_PHY_CONTROL, dev_priv->chv_phy_control);vlv_set_power_well(dev_priv, power_well, false);} @@ -1401,6 +1401,30 @@ static void intel_power_domains_resume(struct drm_i915_private *dev_priv) mutex_unlock(&power_domains->lock); }+static void chv_phy_control_init(struct drm_i915_private *dev_priv)+{ + struct i915_power_well *cmn_bc = + lookup_power_well(dev_priv, PUNIT_POWER_WELL_DPIO_CMN_BC); + struct i915_power_well *cmn_d = + lookup_power_well(dev_priv, PUNIT_POWER_WELL_DPIO_CMN_D); + + /* + * DISPLAY_PHY_CONTROL can get corrupted if read. As a + * workaround never ever read DISPLAY_PHY_CONTROL, and + * instead maintain a shadow copy ourselves. Use the actual + * power well state to reconstruct the expected initial + * value. + */ + dev_priv->chv_phy_control = + PHY_CH_POWER_MODE(PHY_CH_SU_PSR, DPIO_PHY0, DPIO_CH0) | + PHY_CH_POWER_MODE(PHY_CH_SU_PSR, DPIO_PHY0, DPIO_CH1) | + PHY_CH_POWER_MODE(PHY_CH_SU_PSR, DPIO_PHY1, DPIO_CH0); + if (cmn_bc->ops->is_enabled(dev_priv, cmn_bc)) + dev_priv->chv_phy_control |= PHY_COM_LANE_RESET_DEASSERT(DPIO_PHY0); + if (cmn_d->ops->is_enabled(dev_priv, cmn_d)) + dev_priv->chv_phy_control |= PHY_COM_LANE_RESET_DEASSERT(DPIO_PHY1); +} + static void vlv_cmnlane_wa(struct drm_i915_private *dev_priv) { struct i915_power_well *cmn = @@ -1443,7 +1467,9 @@ void intel_power_domains_init_hw(struct drm_i915_private *dev_priv)power_domains->initializing = true; - if (IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {+ if (IS_CHERRYVIEW(dev)) { + chv_phy_control_init(dev_priv); + } else if (IS_VALLEYVIEW(dev)) { mutex_lock(&power_domains->lock); vlv_cmnlane_wa(dev_priv); mutex_unlock(&power_domains->lock);_______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
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