* [PATCH] drm/i915: Use the DVI clock limit in DVI mode
@ 2014-03-25 1:44 Stéphane Marchesin
2014-03-25 8:03 ` Daniel Vetter
0 siblings, 1 reply; 2+ messages in thread
From: Stéphane Marchesin @ 2014-03-25 1:44 UTC (permalink / raw
To: intel-gfx
When using HDMI, the 300MHz clock is legal, but when in DVI mode it's
definitely not. This causes issues when we send a 300MHz signal over a
DVI cable which is specced for 165MHz only. So when in DVI mode let's
limit the clock to 165MHz.
Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
---
drivers/gpu/drm/i915/intel_hdmi.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index dd4fa35..0ac69f1 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -806,6 +806,10 @@ static int hdmi_portclock_limit(struct intel_hdmi *hdmi)
{
struct drm_device *dev = intel_hdmi_to_dev(hdmi);
+ /* If we are in DVI mode, the limit is 165MHz */
+ if (!hdmi->has_hdmi_sink)
+ return 165000;
+
if (IS_G4X(dev))
return 165000;
else if (IS_HASWELL(dev))
--
1.9.1.423.g4596e3a
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] drm/i915: Use the DVI clock limit in DVI mode
2014-03-25 1:44 [PATCH] drm/i915: Use the DVI clock limit in DVI mode Stéphane Marchesin
@ 2014-03-25 8:03 ` Daniel Vetter
0 siblings, 0 replies; 2+ messages in thread
From: Daniel Vetter @ 2014-03-25 8:03 UTC (permalink / raw
To: Stéphane Marchesin; +Cc: intel-gfx
On Tue, Mar 25, 2014 at 2:44 AM, Stéphane Marchesin
<marcheu@chromium.org> wrote:
> When using HDMI, the 300MHz clock is legal, but when in DVI mode it's
> definitely not. This causes issues when we send a 300MHz signal over a
> DVI cable which is specced for 165MHz only. So when in DVI mode let's
> limit the clock to 165MHz.
>
> Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
Is
commit 6375b768a9850b6154478993e5fb566fa4614a9c
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Mon Mar 3 11:33:36 2014 +0200
drm/i915: Reject >165MHz modes w/ DVI monitors
not working for you?
-Daniel
> ---
> drivers/gpu/drm/i915/intel_hdmi.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index dd4fa35..0ac69f1 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -806,6 +806,10 @@ static int hdmi_portclock_limit(struct intel_hdmi *hdmi)
> {
> struct drm_device *dev = intel_hdmi_to_dev(hdmi);
>
> + /* If we are in DVI mode, the limit is 165MHz */
> + if (!hdmi->has_hdmi_sink)
> + return 165000;
> +
> if (IS_G4X(dev))
> return 165000;
> else if (IS_HASWELL(dev))
> --
> 1.9.1.423.g4596e3a
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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