<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO --- - [i915 Bayley Bay] Graphics shake/jitter observed when seen on DP monitor"
href="https://bugs.freedesktop.org/show_bug.cgi?id=75880#c5">Comment # 5</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO --- - [i915 Bayley Bay] Graphics shake/jitter observed when seen on DP monitor"
href="https://bugs.freedesktop.org/show_bug.cgi?id=75880">bug 75880</a>
from <span class="vcard"><a class="email" href="mailto:achandran@mvista.com" title="arun <achandran@mvista.com>"> <span class="fn">arun</span></a>
</span></b>
<pre>Hi,
The below patch solves the problem for me
########################################
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 41bdac4..ad1d824 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -844,12 +844,6 @@ intel_dp_compute_config(struct intel_encoder *encoder,
/* Walk through all bpp values. Luckily they're all nicely spaced with
2
* bpc in between. */
bpp = pipe_config->pipe_bpp;
- if (is_edp(intel_dp) && dev_priv->vbt.edp_bpp &&
- dev_priv->vbt.edp_bpp < bpp) {
- DRM_DEBUG_KMS("clamping bpp for eDP panel to BIOS-provided
%i\n",
- dev_priv->vbt.edp_bpp);
- bpp = dev_priv->vbt.edp_bpp;
- }
for (; bpp >= 6*3; bpp -= 2*3) {
mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
###########################################
In the case of VGA + DP overriding of BIOS provided max bpp is not happening as
intel_dp_get_config() is called after calling intel_dp_compute_config(). That
function overrides pipe bpp with BIOS provided one.
I think it happens because the when both DP and VGA is connected, DP is powered
on lately and intel_dp_get_hw_state() returns false so
intel_modeset_readout_hw_state() is not calling intel_dp_get_config() during
the booting.
Regards,
Arun C</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>