diff mbox

[2/2] video:omapdrm: make omapdrm assume the tv-out cable is always connected

Message ID 5942ddb7ab4f42f207c6c2b54be31a3d9fe3b912.1447410544.git.hns@goldelico.com (mailing list archive)
State New, archived
Headers show

Commit Message

H. Nikolaus Schaller Nov. 13, 2015, 10:29 a.m. UTC
Include VENC in the set of drivers where it is assimed that the cable
is always connected. Like DPI, DSI, DBI and SDI do.

Otherwise, the VENC will return cable status "unknown" and is not enabled
by the X-server. So there is no video output signal.

Tested on: BeagleBoard XM, GTA04 and OpenPandora

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/gpu/drm/omapdrm/omap_connector.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Tomi Valkeinen Nov. 13, 2015, 11:46 a.m. UTC | #1
On 13/11/15 12:29, H. Nikolaus Schaller wrote:
> Include VENC in the set of drivers where it is assimed that the cable
> is always connected. Like DPI, DSI, DBI and SDI do.
> 
> Otherwise, the VENC will return cable status "unknown" and is not enabled
> by the X-server. So there is no video output signal.
> 
> Tested on: BeagleBoard XM, GTA04 and OpenPandora
> 
> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
> ---
>  drivers/gpu/drm/omapdrm/omap_connector.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c b/drivers/gpu/drm/omapdrm/omap_connector.c
> index 83f2a91..98ddb5d 100644
> --- a/drivers/gpu/drm/omapdrm/omap_connector.c
> +++ b/drivers/gpu/drm/omapdrm/omap_connector.c
> @@ -120,6 +120,7 @@ static enum drm_connector_status omap_connector_detect(
>  		else
>  			ret = connector_status_disconnected;
>  	} else if (dssdev->type == OMAP_DISPLAY_TYPE_DPI ||
> +			dssdev->type == OMAP_DISPLAY_TYPE_VENC ||
>  			dssdev->type == OMAP_DISPLAY_TYPE_DBI ||
>  			dssdev->type == OMAP_DISPLAY_TYPE_SDI ||
>  			dssdev->type == OMAP_DISPLAY_TYPE_DSI) {
> 

I have no idea why VENC is not working for you when using
connector_status_unknown, but I just tested DPI with
connector_status_unknown (i.e. changed the above func to return unknown
for DPI), and it works fine with X and X omap driver. And xrandr
confirms that the connection status is unknown:

# xrandr
Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 2048 x 2048
HDMI-1 disconnected (normal left inverted right x axis y axis)
None-1 unknown connection 1920x1200+0+0 (normal left inverted right x
axis y axis) 0mm x 0mm
   1920x1200     60.00*+  60.00 +

Grep also shows that there are many drivers using
connector_status_unknown, so I'm guessing it should work fine...

 Tomi
Laurent Pinchart Nov. 13, 2015, 12:01 p.m. UTC | #2
On Friday 13 November 2015 13:46:01 Tomi Valkeinen wrote:
> On 13/11/15 12:29, H. Nikolaus Schaller wrote:
> > Include VENC in the set of drivers where it is assimed that the cable
> > is always connected. Like DPI, DSI, DBI and SDI do.
> > 
> > Otherwise, the VENC will return cable status "unknown" and is not enabled
> > by the X-server. So there is no video output signal.
> > 
> > Tested on: BeagleBoard XM, GTA04 and OpenPandora
> > 
> > Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
> > ---
> > 
> >  drivers/gpu/drm/omapdrm/omap_connector.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c
> > b/drivers/gpu/drm/omapdrm/omap_connector.c index 83f2a91..98ddb5d 100644
> > --- a/drivers/gpu/drm/omapdrm/omap_connector.c
> > +++ b/drivers/gpu/drm/omapdrm/omap_connector.c
> > @@ -120,6 +120,7 @@ static enum drm_connector_status
> > omap_connector_detect(
> >  		else
> >  			ret = connector_status_disconnected;
> >  	} else if (dssdev->type == OMAP_DISPLAY_TYPE_DPI ||
> > +			dssdev->type == OMAP_DISPLAY_TYPE_VENC ||
> >  			dssdev->type == OMAP_DISPLAY_TYPE_DBI ||
> >  			dssdev->type == OMAP_DISPLAY_TYPE_SDI ||
> >  			dssdev->type == OMAP_DISPLAY_TYPE_DSI) {
> 
> I have no idea why VENC is not working for you when using
> connector_status_unknown, but I just tested DPI with
> connector_status_unknown (i.e. changed the above func to return unknown
> for DPI), and it works fine with X and X omap driver. And xrandr
> confirms that the connection status is unknown:
> 
> # xrandr
> Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 2048 x 2048
> HDMI-1 disconnected (normal left inverted right x axis y axis)
> None-1 unknown connection 1920x1200+0+0 (normal left inverted right x
> axis y axis) 0mm x 0mm
>    1920x1200     60.00*+  60.00 +
> 
> Grep also shows that there are many drivers using
> connector_status_unknown, so I'm guessing it should work fine...

And beside it's not right to consider VENC as always connected, as it isn't. 
The unknown status is there for a reason, to describe connectors for which we 
can't get any status information. The situation is different for DPI, DBI, SDI 
and DSI as those are on-board busses that connect to a non-removable panel, so 
we can say with a good confidence that the panel is connected (the situation 
could be changed with a hammer and a chisel, but that's unlikely to happen, 
hence the confidence).
H. Nikolaus Schaller Nov. 13, 2015, 1:31 p.m. UTC | #3
Hi Laurent and Tomi,

Am 13.11.2015 um 13:01 schrieb Laurent Pinchart <laurent.pinchart@ideasonboard.com>:

> On Friday 13 November 2015 13:46:01 Tomi Valkeinen wrote:
>> On 13/11/15 12:29, H. Nikolaus Schaller wrote:
>>> Include VENC in the set of drivers where it is assimed that the cable
>>> is always connected. Like DPI, DSI, DBI and SDI do.
>>> 
>>> Otherwise, the VENC will return cable status "unknown" and is not enabled
>>> by the X-server. So there is no video output signal.
>>> 
>>> Tested on: BeagleBoard XM, GTA04 and OpenPandora
>>> 
>>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>>> ---
>>> 
>>> drivers/gpu/drm/omapdrm/omap_connector.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>> 
>>> diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c
>>> b/drivers/gpu/drm/omapdrm/omap_connector.c index 83f2a91..98ddb5d 100644
>>> --- a/drivers/gpu/drm/omapdrm/omap_connector.c
>>> +++ b/drivers/gpu/drm/omapdrm/omap_connector.c
>>> @@ -120,6 +120,7 @@ static enum drm_connector_status
>>> omap_connector_detect(
>>> 		else
>>> 			ret = connector_status_disconnected;
>>> 	} else if (dssdev->type == OMAP_DISPLAY_TYPE_DPI ||
>>> +			dssdev->type == OMAP_DISPLAY_TYPE_VENC ||
>>> 			dssdev->type == OMAP_DISPLAY_TYPE_DBI ||
>>> 			dssdev->type == OMAP_DISPLAY_TYPE_SDI ||
>>> 			dssdev->type == OMAP_DISPLAY_TYPE_DSI) {
>> 
>> I have no idea why VENC is not working for you when using
>> connector_status_unknown,

I agree that it should...

>> but I just tested DPI with
>> connector_status_unknown (i.e. changed the above func to return unknown
>> for DPI

Good hint. I can do the same check. Maybe it highlights the real issue.

>> ), and it works fine with X and X omap driver. And xrandr
>> confirms that the connection status is unknown:
>> 
>> # xrandr
>> Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 2048 x 2048
>> HDMI-1 disconnected (normal left inverted right x axis y axis)
>> None-1 unknown connection 1920x1200+0+0 (normal left inverted right x
>> axis y axis) 0mm x 0mm
>>   1920x1200     60.00*+  60.00 +

Which configs, drivers and system are you using for this results?

>> 
>> Grep also shows that there are many drivers using
>> connector_status_unknown, so I'm guessing it should work fine...
> 
> And beside it's not right to consider VENC as always connected, as it isn't. 

Hm. Well, the VENC (meaning the D/A converter inside the OMAP3 chip)
is always connected. But the monitor or cable isn't.

> The unknown status is there for a reason, to describe connectors for which we 
> can't get any status information. The situation is different for DPI, DBI, SDI 
> and DSI as those are on-board busses that connect to a non-removable panel, so 
> we can say with a good confidence that the panel is connected (the situation 
> could be changed with a hammer and a chisel, but that's unlikely to happen, 
> hence the confidence).

Well, it may be that the omapdrm and X11 combination (unfortuantely I don't
understand either and have not found a good description how they interwork),
 keeps the VENC disabled if the connector is unknown.

And since there is no code to detect that a cable has been connected, there
might be missing some trigger to enable the interface.

The symptom I see is that the status of this card is "disabled" while the LCD
panel is "enabled". After doing my proposed patch, both come up "enabled".

So my patch appears to be a work around some other still hidden problem.

Any hint from the experts how to debug / find the real issue & solution is welcome.

BR,
Nikolaus

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H. Nikolaus Schaller Nov. 13, 2015, 4:45 p.m. UTC | #4
Here the test results:

Am 13.11.2015 um 13:01 schrieb Laurent Pinchart <laurent.pinchart@ideasonboard.com>:

> On Friday 13 November 2015 13:46:01 Tomi Valkeinen wrote:
>> On 13/11/15 12:29, H. Nikolaus Schaller wrote:
>>> Include VENC in the set of drivers where it is assimed that the cable
>>> is always connected. Like DPI, DSI, DBI and SDI do.
>>> 
>>> Otherwise, the VENC will return cable status "unknown" and is not enabled
>>> by the X-server. So there is no video output signal.
>>> 
>>> Tested on: BeagleBoard XM, GTA04 and OpenPandora
>>> 
>>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>>> ---
>>> 
>>> drivers/gpu/drm/omapdrm/omap_connector.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>> 
>>> diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c
>>> b/drivers/gpu/drm/omapdrm/omap_connector.c index 83f2a91..98ddb5d 100644
>>> --- a/drivers/gpu/drm/omapdrm/omap_connector.c
>>> +++ b/drivers/gpu/drm/omapdrm/omap_connector.c
>>> @@ -120,6 +120,7 @@ static enum drm_connector_status
>>> omap_connector_detect(
>>> 		else
>>> 			ret = connector_status_disconnected;
>>> 	} else if (dssdev->type == OMAP_DISPLAY_TYPE_DPI ||
>>> +			dssdev->type == OMAP_DISPLAY_TYPE_VENC ||
>>> 			dssdev->type == OMAP_DISPLAY_TYPE_DBI ||
>>> 			dssdev->type == OMAP_DISPLAY_TYPE_SDI ||
>>> 			dssdev->type == OMAP_DISPLAY_TYPE_DSI) {
>> 
>> I have no idea why VENC is not working for you when using
>> connector_status_unknown, but I just tested DPI with
>> connector_status_unknown (i.e. changed the above func to return unknown
>> for DPI), and it works fine with X and X omap driver. And xrandr
>> confirms that the connection status is unknown:
>> 
>> # xrandr
>> Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 2048 x 2048
>> HDMI-1 disconnected (normal left inverted right x axis y axis)
>> None-1 unknown connection 1920x1200+0+0 (normal left inverted right x
>> axis y axis) 0mm x 0mm
>>   1920x1200     60.00*+  60.00 +

A) with this VENC patch:

root@letux:~# xrandr
Screen 0: minimum 320 x 200, current 720 x 640, maximum 2048 x 2048
None-1 connected 720x574+0+0 0mm x 0mm
   720x574i      50.00*+
None-2 connected 480x640+0+0 0mm x 0mm
   480x640       65.74*+
root@letux:~# cat /sys/class/drm/card0-Unknown-*/enabled
enabled
enabled
root@letux:~# cat /sys/class/drm/card0-Unknown-*/status 
connected
connected

B) w/o VENC patch (VENC returns returning connector_status_unknown):

root@letux:~# xrandr
Screen 0: minimum 320 x 200, current 480 x 640, maximum 2048 x 2048
None-1 connected 480x640+0+0 0mm x 0mm
   480x640       65.74*+
None-2 unknown connection
   720x574i      50.00 +
root@letux:~# cat /sys/class/drm/card0-Unknown-*/enabled
enabled
disabled
root@letux:~# cat /sys/class/drm/card0-Unknown-*/status
connected
unknown

C) with DPI (also) returning connector_status_unknown

root@letux:~# xrandr
Screen 0: minimum 320 x 200, current 720 x 640, maximum 2048 x 2048
None-1 unknown connection 720x574+0+0 0mm x 0mm
   720x574i      50.00*+
None-2 unknown connection 480x640+0+0 0mm x 0mm
   480x640       65.74*+
root@letux:~# cat /sys/class/drm/card0-Unknown-*/enabled
enabled
enabled
root@letux:~# cat /sys/class/drm/card0-Unknown-*/status
unknown
unknown
root@letux:~# 

D) VENC patch but DPI returning connector_status_unknown

rroot@letux:~# xrandr
Screen 0: minimum 320 x 200, current 720 x 574, maximum 2048 x 2048
None-1 unknown connection
   480x640       65.74 +
None-2 connected 720x574+0+0 0mm x 0mm
   720x574i      50.00*+oot@letux:~# cat /sys/class/drm/card0-Unknown-*/enabled
disabled
enabled
root@letux:~# cat /sys/class/drm/card0-Unknown-*/status
unknown
connected

In case B) I have no TV out and in case D) I have no LCD.

So it looks as if it works if my LCD and VENC report the same
connection status. And fails if they differ.

Anyone with an explanation or even vague idea where to search
for the real bug?

BR and thanks,
Nikolaus

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diff mbox

Patch

diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c b/drivers/gpu/drm/omapdrm/omap_connector.c
index 83f2a91..98ddb5d 100644
--- a/drivers/gpu/drm/omapdrm/omap_connector.c
+++ b/drivers/gpu/drm/omapdrm/omap_connector.c
@@ -120,6 +120,7 @@  static enum drm_connector_status omap_connector_detect(
 		else
 			ret = connector_status_disconnected;
 	} else if (dssdev->type == OMAP_DISPLAY_TYPE_DPI ||
+			dssdev->type == OMAP_DISPLAY_TYPE_VENC ||
 			dssdev->type == OMAP_DISPLAY_TYPE_DBI ||
 			dssdev->type == OMAP_DISPLAY_TYPE_SDI ||
 			dssdev->type == OMAP_DISPLAY_TYPE_DSI) {