Re: [PATCH 2/5] host1x: hdmi: Detect whether display is connectedwith HDMI or DVI

[Mikko Perttunen]

On 08/28/2013 03:07 PM, Thierry Reding wrote:
> * PGP Signed by an unknown key
>
> On Wed, Aug 28, 2013 at 01:40:56PM +0300, Mikko Perttunen wrote:
> > Use EDID data to determine whether the display supports HDMI or just DVI.
> > This used to be hardcoded to be HDMI, which broke support for DVI displays
> > that couldn't understand the interspersed audio/other data.
> >
> > If the EDID data isn't available, default to DVI, which should be a safer
> > choice.
> >
> > Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> > ---
> >   drivers/gpu/host1x/drm/hdmi.c | 8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/gpu/host1x/drm/hdmi.c b/drivers/gpu/host1x/drm/hdmi.c
> > index d81fac8..140339b 100644
> > --- a/drivers/gpu/host1x/drm/hdmi.c
> > +++ b/drivers/gpu/host1x/drm/hdmi.c
> > @@ -702,6 +702,14 @@ static int tegra_output_hdmi_enable(struct tegra_output *output)
> >   	unsigned long value;
> >   	int retries = 1000;
> >   	int err;
> > +	struct drm_property_blob *edid_blob = output->connector.edid_blob_ptr;
> > +
> > +	if (edid_blob && edid_blob->data &&
> > +		drm_detect_hdmi_monitor((struct edid *)edid_blob->data)) {
> > +		hdmi->dvi = false;
> > +	} else {
> > +		hdmi->dvi = true;
> > +	}
> >
> >   	pclk = mode->clock * 1000;
> >   	h_sync_width = mode->hsync_end - mode->hsync_start;
>
> Odd, now that I see that code I remember that there was a similar patch
> a few months back, but it was never applied for some reason:
>
> 	http://lists.freedesktop.org/archives/dri-devel/2013-January/033509.html
>
> That was already reviewed by me and Jon Mayo, so I'll go ahead and apply
> that one instead.
>
> Thierry
>
> * Unknown Key
> * 0x7F3EB3A1

That patch seems to cause a warning for me:
drivers/gpu/host1x/drm/hdmi.c: In function ‘tegra_output_hdmi_enable’:
drivers/gpu/host1x/drm/hdmi.c:706:2: warning: passing argument 1 of 
‘drm_detect_hdmi_monitor’ discards ‘const’ qualifier from pointer target 
type [enabled by default]
include/drm/drm_crtc.h:1037:13: note: expected ‘struct edid *’ but 
argument is of type ‘const struct edid *’

Looks much nicer though.
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