drm/i915: implement timing override workarounds on LPT

These workarounds are documented on the CRT mode set sequence.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Paulo Zanoni 2012-10-31 18:12:52 -02:00 committed by Daniel Vetter
parent 8a52fd9f24
commit 223a6fdfbf

View File

@ -1729,6 +1729,11 @@ static void lpt_enable_pch_transcoder(struct drm_i915_private *dev_priv,
assert_fdi_tx_enabled(dev_priv, cpu_transcoder);
assert_fdi_rx_enabled(dev_priv, TRANSCODER_A);
/* Workaround: set timing override bit. */
val = I915_READ(_TRANSA_CHICKEN2);
val |= TRANS_AUTOTRAIN_GEN_STALL_DIS;
I915_WRITE(_TRANSA_CHICKEN2, val);
val = TRANS_ENABLE;
pipeconf_val = I915_READ(PIPECONF(cpu_transcoder));
@ -1780,6 +1785,11 @@ static void lpt_disable_pch_transcoder(struct drm_i915_private *dev_priv,
/* wait for PCH transcoder off, transcoder state */
if (wait_for((I915_READ(_TRANSACONF) & TRANS_STATE_ENABLE) == 0, 50))
DRM_ERROR("Failed to disable PCH transcoder\n");
/* Workaround: clear timing override bit. */
val = I915_READ(_TRANSA_CHICKEN2);
val &= ~TRANS_AUTOTRAIN_GEN_STALL_DIS;
I915_WRITE(_TRANSA_CHICKEN2, val);
}
/**