[PATCH 2/4] drm/i915: fix Haswell FDI link training code

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This is wrong.... Ignore it. I messed up rebasing it against the new patches.

2012/11/1 Paulo Zanoni <przanoni at gmail.com>:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>
> This commit makes hsw_fdi_link_train responsible for implementing
> everything described in the "Enable and train FDI" section from the
> Hawell CRT mode set sequence documentation. We completely rewrite
> hsw_fdi_link_train to match the documentation and we also call it in
> the right place.
>
> This patch was initially sent as a series of tiny patches fixing every
> little problem of the function, but since there were too many patches
> fixing the same function it got a little difficult to get the "big
> picture" of how the function would be in the end, so here we amended
> all the patches into a single big patch fixing the whole function.
>
> Problems we fixed:
>
>   1 - Train Haswell FDI at the right time.
>
>     We need to train the FDI before enabling the pipes and planes, so
>     we're moving the call from lpt_pch_enable to haswell_crtc_enable
>     directly.
>
>     We are also removing ironlake_fdi_pll_enable since the PLL
>     enablement on Haswell is completely different and is also done
>     during the link training steps.
>
>   2 - Use the right FDI_RX_CTL register on Haswell
>
>     There is only one PCH transcoder, so it's always _FDI_RXA_CTL.
>     Using "pipe" here is wrong.
>
>   3 - Don't rely on DDI_BUF_CTL previous values
>
>     Just set the bits we want, everything else is zero. Also
>     POSTING_READ the register before sleeping.
>
>   4 - Program the FDI RX TUSIZE register on hsw_fdi_link_train
>
>     According to the mode set sequence documentation, this is the
>     right place. According to the FDI_RX_TUSIZE register description,
>     this is the value we should set.
>
>     Also remove the code that sets this register from the old
>     location: lpt_pch_enable.
>
>   5 - Properly program FDI_RX_MISC pwrdn lane values on HSW
>
>   6 - Wait only 35us for the FDI link training
>
>     First we wait 30us for the FDI receiver lane calibration, then we
>     wait 5us for the FDI auto training time.
>
>   7 - Remove an useless indentation level on hsw_fdi_link_train
>
>     We already "break" when the link training succeeds.
>
>   8 - Disable FDI_RX_ENABLE, not FDI_RX_PLL_ENABLE
>
>     When we fail the training.
>
>   9 - Change Haswell FDI link training error messages
>
>     We shouldn't call DRM_ERROR when still looping through voltage
>     levels since this is expected and not really a failure. So in this
>     commit we adjust the error path to only DRM_ERROR when we really
>     fail after trying everything.
>
>     While at it, replace DRM_DEBUG_DRIVER with DRM_DEBUG_KMS since
>     it's what we use everywhere.
>
>   10 - Try each voltage twice at hsw_fdi_link_train
>
>     Now with Daniel Vetter's suggestion to use "/2" instead of ">>1".
>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      |  17 ++++--
>  drivers/gpu/drm/i915/intel_ddi.c     | 108 +++++++++++++++++++++--------------
>  drivers/gpu/drm/i915/intel_display.c |  11 +---
>  3 files changed, 76 insertions(+), 60 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index d4520d5..a167d76 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3924,16 +3924,21 @@
>  #define  FDI_PORT_WIDTH_2X_LPT                 (1<<19)
>  #define  FDI_PORT_WIDTH_1X_LPT                 (0<<19)
>
> -#define _FDI_RXA_MISC            0xf0010
> -#define _FDI_RXB_MISC            0xf1010
> +#define _FDI_RXA_MISC                  0xf0010
> +#define _FDI_RXB_MISC                  0xf1010
> +#define  FDI_RX_PWRDN_LANE1_MASK       (3<<26)
> +#define  FDI_RX_PWRDN_LANE1_VAL(x)     ((x)<<26)
> +#define  FDI_RX_PWRDN_LANE0_MASK       (3<<24)
> +#define  FDI_RX_PWRDN_LANE0_VAL(x)     ((x)<<24)
> +#define  FDI_RX_TP1_TO_TP2_48          (2<<20)
> +#define  FDI_RX_TP1_TO_TP2_64          (3<<20)
> +#define  FDI_RX_FDI_DELAY_90           (0x90<<0)
> +#define FDI_RX_MISC(pipe) _PIPE(pipe, _FDI_RXA_MISC, _FDI_RXB_MISC)
> +
>  #define _FDI_RXA_TUSIZE1         0xf0030
>  #define _FDI_RXA_TUSIZE2         0xf0038
>  #define _FDI_RXB_TUSIZE1         0xf1030
>  #define _FDI_RXB_TUSIZE2         0xf1038
> -#define  FDI_RX_TP1_TO_TP2_48  (2<<20)
> -#define  FDI_RX_TP1_TO_TP2_64  (3<<20)
> -#define  FDI_RX_FDI_DELAY_90   (0x90<<0)
> -#define FDI_RX_MISC(pipe) _PIPE(pipe, _FDI_RXA_MISC, _FDI_RXB_MISC)
>  #define FDI_RX_TUSIZE1(pipe) _PIPE(pipe, _FDI_RXA_TUSIZE1, _FDI_RXB_TUSIZE1)
>  #define FDI_RX_TUSIZE2(pipe) _PIPE(pipe, _FDI_RXA_TUSIZE2, _FDI_RXB_TUSIZE2)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index a7a555f..92c2d61 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -153,11 +153,33 @@ void hsw_fdi_link_train(struct drm_crtc *crtc)
>         struct drm_device *dev = crtc->dev;
>         struct drm_i915_private *dev_priv = dev->dev_private;
>         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> -       int pipe = intel_crtc->pipe;
> -       u32 reg, temp, i;
> +       u32 temp, i, rx_ctl_val;
> +
> +       /* Set the FDI_RX_MISC pwrdn lanes and the 2 workarounds listed at the
> +        * mode set "sequence for CRT port" document:
> +        * - TP1 to TP2 time with the default value
> +        * - FDI delay to 90h
> +        */
> +       I915_WRITE(_FDI_RXA_MISC, FDI_RX_PWRDN_LANE1_VAL(2) |
> +                                 FDI_RX_PWRDN_LANE0_VAL(2) |
> +                                 FDI_RX_TP1_TO_TP2_48 | FDI_RX_FDI_DELAY_90);
> +
> +       /* Enable the PCH Receiver FDI PLL */
> +       rx_ctl_val = FDI_RX_PLL_ENABLE | FDI_RX_ENHANCE_FRAME_ENABLE |
> +                    ((intel_crtc->fdi_lanes - 1) << 19);
> +       I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
> +       POSTING_READ(_FDI_RXA_CTL);
> +       udelay(220);
> +
> +       /* Switch from Rawclk to PCDclk */
> +       rx_ctl_val |= FDI_PCDCLK;
> +       I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
> +
> +       /* Configure Port Clock Select */
> +       I915_WRITE(PORT_CLK_SEL(PORT_E), intel_crtc->ddi_pll_sel);
>
>         /* Start the training iterating through available voltages and emphasis */
> -       for (i=0; i < ARRAY_SIZE(hsw_ddi_buf_ctl_values); i++) {
> +       for (i = 0; i < ARRAY_SIZE(hsw_ddi_buf_ctl_values) * 2; i++) {
>                 /* Configure DP_TP_CTL with auto-training */
>                 I915_WRITE(DP_TP_CTL(PORT_E),
>                                         DP_TP_CTL_FDI_AUTOTRAIN |
> @@ -166,41 +188,37 @@ void hsw_fdi_link_train(struct drm_crtc *crtc)
>                                         DP_TP_CTL_ENABLE);
>
>                 /* Configure and enable DDI_BUF_CTL for DDI E with next voltage */
> -               temp = I915_READ(DDI_BUF_CTL(PORT_E));
> -               temp = (temp & ~DDI_BUF_EMP_MASK);
>                 I915_WRITE(DDI_BUF_CTL(PORT_E),
> -                               temp |
> -                               DDI_BUF_CTL_ENABLE |
> -                               ((intel_crtc->fdi_lanes - 1) << 1) |
> -                               hsw_ddi_buf_ctl_values[i]);
> +                          DDI_BUF_CTL_ENABLE |
> +                          ((intel_crtc->fdi_lanes - 1) << 1) |
> +                          hsw_ddi_buf_ctl_values[i / 2]);
> +               POSTING_READ(DDI_BUF_CTL(PORT_E));
>
>                 udelay(600);
>
> -               /* We need to program FDI_RX_MISC with the default TP1 to TP2
> -                * values before enabling the receiver, and configure the delay
> -                * for the FDI timing generator to 90h. Luckily, all the other
> -                * bits are supposed to be zeroed, so we can write those values
> -                * directly.
> -                */
> -               I915_WRITE(FDI_RX_MISC(pipe), FDI_RX_TP1_TO_TP2_48 |
> -                               FDI_RX_FDI_DELAY_90);
> -
> -               /* Enable CPU FDI Receiver with auto-training */
> -               reg = FDI_RX_CTL(pipe);
> -               I915_WRITE(reg,
> -                               I915_READ(reg) |
> -                                       FDI_LINK_TRAIN_AUTO |
> -                                       FDI_RX_ENABLE |
> -                                       FDI_LINK_TRAIN_PATTERN_1_CPT |
> -                                       FDI_RX_ENHANCE_FRAME_ENABLE |
> -                                       ((intel_crtc->fdi_lanes - 1) << 19) |
> -                                       FDI_RX_PLL_ENABLE);
> -               POSTING_READ(reg);
> -               udelay(100);
> +               /* Program PCH FDI Receiver TU */
> +               I915_WRITE(_FDI_RXA_TUSIZE1, TU_SIZE(64));
> +
> +               /* Enable PCH FDI Receiver with auto-training */
> +               rx_ctl_val |= FDI_RX_ENABLE | FDI_LINK_TRAIN_AUTO;
> +               I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
> +               POSTING_READ(_FDI_RXA_CTL);
> +
> +               /* Wait for FDI receiver lane calibration */
> +               udelay(30);
> +
> +               /* Unset FDI_RX_MISC pwrdn lanes */
> +               temp = I915_READ(_FDI_RXA_MISC);
> +               temp &= ~(FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK);
> +               I915_WRITE(_FDI_RXA_MISC, temp);
> +               POSTING_READ(_FDI_RXA_MISC);
> +
> +               /* Wait for FDI auto training time */
> +               udelay(5);
>
>                 temp = I915_READ(DP_TP_STATUS(PORT_E));
>                 if (temp & DP_TP_STATUS_AUTOTRAIN_DONE) {
> -                       DRM_DEBUG_DRIVER("BUF_CTL training done on %d step\n", i);
> +                       DRM_DEBUG_KMS("FDI link training done on step %d\n", i);
>
>                         /* Enable normal pixel sending for FDI */
>                         I915_WRITE(DP_TP_CTL(PORT_E),
> @@ -209,22 +227,24 @@ void hsw_fdi_link_train(struct drm_crtc *crtc)
>                                                 DP_TP_CTL_ENHANCED_FRAME_ENABLE |
>                                                 DP_TP_CTL_ENABLE);
>
> -                       break;
> -               } else {
> -                       DRM_ERROR("Error training BUF_CTL %d\n", i);
> -
> -                       /* Disable DP_TP_CTL and FDI_RX_CTL) and retry */
> -                       I915_WRITE(DP_TP_CTL(PORT_E),
> -                                       I915_READ(DP_TP_CTL(PORT_E)) &
> -                                               ~DP_TP_CTL_ENABLE);
> -                       I915_WRITE(FDI_RX_CTL(pipe),
> -                                       I915_READ(FDI_RX_CTL(pipe)) &
> -                                               ~FDI_RX_PLL_ENABLE);
> -                       continue;
> +                       return;
>                 }
> +
> +               /* Disable DP_TP_CTL and FDI_RX_CTL and retry */
> +               I915_WRITE(DP_TP_CTL(PORT_E),
> +                          I915_READ(DP_TP_CTL(PORT_E)) & ~DP_TP_CTL_ENABLE);
> +
> +               rx_ctl_val &= ~FDI_RX_ENABLE;
> +               I915_WRITE(_FDI_RXA_CTL, rx_ctl_val);
> +
> +               /* Reset FDI_RX_MISC pwrdn lanes */
> +               temp = I915_READ(_FDI_RXA_MISC);
> +               temp &= ~(FDI_RX_PWRDN_LANE1_MASK | FDI_RX_PWRDN_LANE0_MASK);
> +               temp |= FDI_RX_PWRDN_LANE1_VAL(2) | FDI_RX_PWRDN_LANE0_VAL(2);
> +               I915_WRITE(_FDI_RXA_MISC, temp);
>         }
>
> -       DRM_DEBUG_KMS("FDI train done.\n");
> +       DRM_ERROR("FDI link training failed!\n");
>  }
>
>  /* WRPLL clock dividers */
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 14ea479..69ed903 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3114,9 +3114,6 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
>         I915_WRITE(FDI_RX_TUSIZE1(pipe),
>                    I915_READ(PIPE_DATA_M1(pipe)) & TU_SIZE_MASK);
>
> -       /* For PCH output, training FDI link */
> -       dev_priv->display.fdi_link_train(crtc);
> -
>         /* XXX: pch pll's can be enabled any time before we enable the PCH
>          * transcoder, and we actually should do this to not upset any PCH
>          * transcoder that already use the clock when we share it.
> @@ -3209,16 +3206,10 @@ static void lpt_pch_enable(struct drm_crtc *crtc)
>         struct drm_device *dev = crtc->dev;
>         struct drm_i915_private *dev_priv = dev->dev_private;
>         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> -       int pipe = intel_crtc->pipe;
>         enum transcoder cpu_transcoder = intel_crtc->cpu_transcoder;
>
>         assert_transcoder_disabled(dev_priv, TRANSCODER_A);
>
> -       /* Write the TU size bits before fdi link training, so that error
> -        * detection works. */
> -       I915_WRITE(FDI_RX_TUSIZE1(pipe),
> -                  I915_READ(PIPE_DATA_M1(pipe)) & TU_SIZE_MASK);
> -
>         /* For PCH output, training FDI link */
>         dev_priv->display.fdi_link_train(crtc);
>
> @@ -3451,7 +3442,7 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
>         is_pch_port = haswell_crtc_driving_pch(crtc);
>
>         if (is_pch_port)
> -               ironlake_fdi_pll_enable(intel_crtc);
> +               dev_priv->display.fdi_link_train(crtc);
>
>         for_each_encoder_on_crtc(dev, crtc, encoder)
>                 if (encoder->pre_enable)
> --
> 1.7.11.4
>



-- 
Paulo Zanoni


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