Re: i915: 2.6.36-rc2 wrong resolution on gdm start

Chris Wilson
2010-08-24T07:49:49Z

On Tue, 24 Aug 2010 03:00:55 +0200, Ivan Bulatovic <combuster@gmx.com> wrote:
> While in init3, resolution is native, KMS works fine, no problems at
> all. As soon as gdm starts it seems that TV1 output is recognized as
> connected even if it isn't so resolution on VGA output is degraded from
> native 1280x1024 to 1024x768 on startup.

Interesting. I am chasing a spurious TV connection on SDVO that has been
present since time immemorial. How certain are you that you've never have a
false detection in earlier kernels? It may not have affected the choice of
outputs, except sporadically, but it should be recorded in the debug logs
with drm.debug=0x6.

Does this make any difference?

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c
b/drivers/gpu/drm/i915/intel_sdvo
index ea2f4ab..e7ff378 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1454,7 +1454,7 @@ intel_sdvo_detect(struct drm_connector *connector,
return connector_status_unknown;
if (intel_sdvo->is_tv) {
/* add 30ms delay when the output type is SDVO-TV */
- mdelay(30);
+ mdelay(100);
}
if (!intel_sdvo_read_response(intel_sdvo, &response, 2))
return connector_status_unknown;

Or (more likely):

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c
b/drivers/gpu/drm/i915/intel_sdvo
index ea2f4ab..77c455b 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1216,8 +1216,8 @@ static int intel_sdvo_dpms(struct drm_encoder
*encoder, in
temp = I915_READ(intel_sdvo->sdvo_reg);
if ((temp & SDVO_ENABLE) == 0)
intel_sdvo_write_sdvox(intel_sdvo, temp |
SDVO_ENABLE);
- for (i = 0; i < 2; i++)
- intel_wait_for_vblank(dev, intel_crtc->pipe);
+
+ msleep(100);

status = intel_sdvo_get_trained_inputs(intel_sdvo,
&input1, &input2);

--
Chris Wilson, Intel Open Source Technology Centre