Re: omap DSS cmdline resolution not working for HDMI?

On Fri, 2012-10-05 at 09:43 -0700, Tony Lindgren wrote:

Looks like somehow also output_size won't change when changing
display output from DVI to HDMI.

If I boot with DVI panel at 1600x1200, then try to switch to the
HDMI monitor with the following script:

#!/bin/sh

export dvi=display0
export hdmi=display1
export overlay=overlay0

echo 0 > /sys/devices/platform/omapdss/$dvi/enabled
echo 1 > /sys/devices/platform/omapdss/$hdmi/enabled
echo "85500,1366/70/213/143,768/3/24/3" > /sys/devices/platform/omapdss/$hdmi/timings
echo 0 > /sys/devices/platform/omapdss/$overlay/enabled
echo tv > /sys/devices/platform/omapdss/$overlay/manager
#echo "1366,768" > /sys/devices/platform/omapdss/$overlay/output_size
echo 1 > /sys/devices/platform/omapdss/$overlay/enabled
cat /sys/devices/platform/omapdss/$hdmi/timings
cat /sys/devices/platform/omapdss/$overlay/output_size

I get the following which may provide more clues:

[64370.820312] omapdss DISPC error: SYNC_LOST on channel tv, restarting the output with video overlays dd
[64370.831024] omapdss OVERLAY error: overlay 0 horizontally not inside the display area (0 + 1600 >= 13)
[64370.840972] omapdss APPLY error: failed to enable manager 1: check_settings failed
[64370.849670] omapdss HDMI error: failed to power on device
[64370.855407] omapdss error: failed to power on
[64370.862487] omapdss OVERLAY error: overlay 0 horizontally not inside the display area (0 + 1600 >= 13)
[64370.872436] omapdss APPLY error: failed to enable manager 1: check_settings failed
[64370.880798] omapdss HDMI error: failed to power on device
[64370.886505] omapdss error: failed to power on
85500,1366/70/213/143,768/3/24/3
1600,1200

Well, it's not that simple =). There are three things to consider:

- Framebuffer in the sdram. It has xres and yres parameters.
- Overlay, and it's input size (from fb) and output sizes (must fit into
the display).
- Display, which has certain size depending on video mode.

Only VID overlays can have different input and output sizes, GFX overlay
does not support scaling.

In the script above you don't change the fb at all. You can do that with
when the overlay is disabled, for example:

fbset -xres 1366 -vxres 1366 -yres 768 -vyres 768

But that only works if there's enough memory allocated for the
framebuffer, but that is the case for you if the fb was bigger
initially. Otherwise you need to set the new size
with /sys/class/graphics/fb0/size before resizing the fb.

And, of course, the framebuffer cannot be in use at that time by, for
example, X.

Yes, it's complex! I hope omapdrm will make all things simple, and we
can forget omapfb. In hindsight, I should've designed omapfb to be much
simpler, and only use gfx overlay. Making it support all overlays is a
never ending source for problems and complexity.

FYI, I'm also seeing the DVI monitor blank out on it's own for
about a second or so on regular basis every 10 minutes or so.
No idea what's causing that, maybe it's a reminder to take
a short break :)

Well that's something different. I've recently done some testing with
using DSI PLL for generating pixel clock, and I've seen unstabilities
with that. But perhaps there's something else wrong also, even when
using the PRCM for pix clock as in your case.

Does your monitor ever report something like bad signal or such?

 Tomi