[Intel-gfx] [PATCH] drm/i915: make IVB FDI training match spec v3
Paulo Zanoni
przanoni at gmail.com
Mon Aug 19 22:18:47 CEST 2013
2013/8/19 Jesse Barnes <jbarnes at virtuousgeek.org>:
> The existing code was trying different vswing and preemphasis settings
> in the wrong place, and wasn't trying them enough. So add a loop to
> walk through them, properly disabling FDI TX and RX in between if a
> failure is detected.
>
> v2: remove unneeded reg writes, add delays around bit lock checks (Jesse)
> v3: fix TX and RX disable per spec (Paulo)
> fix delays per spec (Paulo)
> make RX symbol lock check match TX bit lock check (Paulo)
>
> Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
> drivers/gpu/drm/i915/intel_display.c | 142 +++++++++++++++++-----------------
> 1 file changed, 72 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 00114a5..0f40f8e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2597,7 +2597,7 @@ static void ivb_manual_fdi_link_train(struct drm_crtc *crtc)
> 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 reg, temp, i, j;
>
> /* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
> for train result */
> @@ -2613,97 +2613,99 @@ static void ivb_manual_fdi_link_train(struct drm_crtc *crtc)
> DRM_DEBUG_KMS("FDI_RX_IIR before link train 0x%x\n",
> I915_READ(FDI_RX_IIR(pipe)));
>
> - /* enable CPU FDI TX and PCH FDI RX */
> - reg = FDI_TX_CTL(pipe);
> - temp = I915_READ(reg);
> - temp &= ~FDI_DP_PORT_WIDTH_MASK;
> - temp |= FDI_DP_PORT_WIDTH(intel_crtc->config.fdi_lanes);
> - temp &= ~(FDI_LINK_TRAIN_AUTO | FDI_LINK_TRAIN_NONE_IVB);
> - temp |= FDI_LINK_TRAIN_PATTERN_1_IVB;
> - temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
> - temp |= FDI_LINK_TRAIN_400MV_0DB_SNB_B;
> - temp |= FDI_COMPOSITE_SYNC;
> - I915_WRITE(reg, temp | FDI_TX_ENABLE);
> -
> - I915_WRITE(FDI_RX_MISC(pipe),
> - FDI_RX_TP1_TO_TP2_48 | FDI_RX_FDI_DELAY_90);
> -
> - reg = FDI_RX_CTL(pipe);
> - temp = I915_READ(reg);
> - temp &= ~FDI_LINK_TRAIN_AUTO;
> - temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
> - temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
> - temp |= FDI_COMPOSITE_SYNC;
> - I915_WRITE(reg, temp | FDI_RX_ENABLE);
> + /* Try each vswing and preemphasis setting twice before moving on */
> + for (j = 0; j < ARRAY_SIZE(snb_b_fdi_train_param) * 2; j++) {
> + /* disable first in case we need to retry */
> + reg = FDI_TX_CTL(pipe);
> + temp = I915_READ(reg);
> + temp &= ~(FDI_LINK_TRAIN_AUTO | FDI_LINK_TRAIN_NONE_IVB);
> + temp &= ~FDI_TX_ENABLE;
> + I915_WRITE(reg, temp);
>
> - POSTING_READ(reg);
> - udelay(150);
> + reg = FDI_RX_CTL(pipe);
> + temp = I915_READ(reg);
> + temp &= ~FDI_LINK_TRAIN_AUTO;
> + temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
> + temp &= ~FDI_RX_ENABLE;
> + I915_WRITE(reg, temp);
>
> - for (i = 0; i < 4; i++) {
> + /* enable CPU FDI TX and PCH FDI RX */
> reg = FDI_TX_CTL(pipe);
> temp = I915_READ(reg);
> + temp &= ~FDI_DP_PORT_WIDTH_MASK;
> + temp |= FDI_DP_PORT_WIDTH(intel_crtc->config.fdi_lanes);
> + temp |= FDI_LINK_TRAIN_PATTERN_1_IVB;
> temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
> - temp |= snb_b_fdi_train_param[i];
> - I915_WRITE(reg, temp);
> + temp |= snb_b_fdi_train_param[j/2];
> + temp |= FDI_COMPOSITE_SYNC;
> + I915_WRITE(reg, temp | FDI_TX_ENABLE);
>
> - POSTING_READ(reg);
> - udelay(500);
> + I915_WRITE(FDI_RX_MISC(pipe),
> + FDI_RX_TP1_TO_TP2_48 | FDI_RX_FDI_DELAY_90);
>
> - reg = FDI_RX_IIR(pipe);
> + reg = FDI_RX_CTL(pipe);
> temp = I915_READ(reg);
> - DRM_DEBUG_KMS("FDI_RX_IIR 0x%x\n", temp);
> -
> - if (temp & FDI_RX_BIT_LOCK ||
> - (I915_READ(reg) & FDI_RX_BIT_LOCK)) {
> - I915_WRITE(reg, temp | FDI_RX_BIT_LOCK);
> - DRM_DEBUG_KMS("FDI train 1 done, level %i.\n", i);
> - break;
> - }
> - }
> - if (i == 4)
> - DRM_ERROR("FDI train 1 fail!\n");
> + temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
> + temp |= FDI_COMPOSITE_SYNC;
> + I915_WRITE(reg, temp | FDI_RX_ENABLE);
>
> - /* Train 2 */
> - reg = FDI_TX_CTL(pipe);
> - temp = I915_READ(reg);
> - temp &= ~FDI_LINK_TRAIN_NONE_IVB;
> - temp |= FDI_LINK_TRAIN_PATTERN_2_IVB;
> - temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
> - temp |= FDI_LINK_TRAIN_400MV_0DB_SNB_B;
> - I915_WRITE(reg, temp);
> + POSTING_READ(reg);
> + udelay(1); /* should be 0.5us */
>
> - reg = FDI_RX_CTL(pipe);
> - temp = I915_READ(reg);
> - temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
> - temp |= FDI_LINK_TRAIN_PATTERN_2_CPT;
> - I915_WRITE(reg, temp);
> + for (i = 0; i < 4; i++) {
> + reg = FDI_RX_IIR(pipe);
> + temp = I915_READ(reg);
> + DRM_DEBUG_KMS("FDI_RX_IIR 0x%x\n", temp);
>
> - POSTING_READ(reg);
> - udelay(150);
> + if (temp & FDI_RX_BIT_LOCK ||
> + (I915_READ(reg) & FDI_RX_BIT_LOCK)) {
> + I915_WRITE(reg, temp | FDI_RX_BIT_LOCK);
> + DRM_DEBUG_KMS("FDI train 1 done, level %i.\n",
> + i);
> + break;
> + }
> + udelay(1); /* should be 0.5us */
> + }
> + if (i == 4) {
> + DRM_DEBUG_KMS("FDI train 1 fail on vswing %d\n", j / 2);
> + continue;
> + }
>
> - for (i = 0; i < 4; i++) {
> + /* Train 2 */
> reg = FDI_TX_CTL(pipe);
> temp = I915_READ(reg);
> - temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
> - temp |= snb_b_fdi_train_param[i];
> + temp &= ~FDI_LINK_TRAIN_NONE_IVB;
> + temp |= FDI_LINK_TRAIN_PATTERN_2_IVB;
> + I915_WRITE(reg, temp);
> +
> + reg = FDI_RX_CTL(pipe);
> + temp = I915_READ(reg);
> + temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
> + temp |= FDI_LINK_TRAIN_PATTERN_2_CPT;
> I915_WRITE(reg, temp);
>
> POSTING_READ(reg);
> - udelay(500);
> + udelay(2); /* should be 1.5us */
>
> - reg = FDI_RX_IIR(pipe);
> - temp = I915_READ(reg);
> - DRM_DEBUG_KMS("FDI_RX_IIR 0x%x\n", temp);
> + for (i = 0; i < 4; i++) {
> + reg = FDI_RX_IIR(pipe);
> + temp = I915_READ(reg);
> + DRM_DEBUG_KMS("FDI_RX_IIR 0x%x\n", temp);
>
> - if (temp & FDI_RX_SYMBOL_LOCK) {
> - I915_WRITE(reg, temp | FDI_RX_SYMBOL_LOCK);
> - DRM_DEBUG_KMS("FDI train 2 done, level %i.\n", i);
> - break;
> + if (temp & FDI_RX_SYMBOL_LOCK ||
> + (I915_READ(reg) & FDI_RX_SYMBOL_LOCK)) {
> + I915_WRITE(reg, temp | FDI_RX_SYMBOL_LOCK);
> + DRM_DEBUG_KMS("FDI train 2 done, level %i.\n",
> + i);
> + goto train_done;
> + }
> + udelay(2); /* should be 1.5us */
> }
> + if (i == 4)
> + DRM_DEBUG_KMS("FDI train 2 fail on vswing %d\n", j / 2);
> }
> - if (i == 4)
> - DRM_ERROR("FDI train 2 fail!\n");
>
> +train_done:
> DRM_DEBUG_KMS("FDI train done.\n");
> }
>
> --
> 1.7.9.5
>
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--
Paulo Zanoni
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