[Intel-gfx] [PATCH] drm/i915: make IVB FDI training match spec v3
Jesse Barnes
jbarnes at virtuousgeek.org
Mon Aug 19 20:04:55 CEST 2013
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>
---
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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