[Intel-gfx] [PATCH] drm/i915: Use the DVI clock limit in DVI mode

[Daniel Vetter]

On Tue, Mar 25, 2014 at 2:44 AM, Stéphane Marchesin
<marcheu at 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 at chromium.org>

Is

commit 6375b768a9850b6154478993e5fb566fa4614a9c
Author: Ville Syrjälä <ville.syrjala at 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 at 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