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[2/5] host1x: hdmi: Detect whether display is connected with HDMI or DVI

Message ID 1377686459-16634-3-git-send-email-mperttunen@nvidia.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mikko Perttunen Aug. 28, 2013, 10:40 a.m. UTC
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@nvidia.com>
---
 drivers/gpu/host1x/drm/hdmi.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Mikko Perttunen Aug. 28, 2013, 12:34 p.m. UTC | #1
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@nvidia.com>
>> ---
>>   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.
diff mbox

Patch

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;