Re: [pandaboard] Changing screen resolution on Linaro Developer Build

[Rob Clark]

See http://nouveau.freedesktop.org/wiki/KernelModeSetting and scroll
down to 'Forcing Modes'.. this will work the same w/ the omapdrm
driver, so a bootarg like:

video="HDMI Type A-1:800x600"

To change resolution at runtime, your app should use the KMS APIs
(this is what xf86-video-omap does to implement xrandr, and what
wayland weston compositor does)

BR,
-R

On Fri, Aug 24, 2012 at 7:46 AM, <swig...@googlemail.com> wrote:
> As the title says, I can't change the resolution on the pandaboard using the
> console-based Linaro Developer build. I've tried with fbset and by editing
> and re-building boot.scr, but neither works. I would like to know if there
> is a way to change resolution on the fly, without requiring a reboot.
>
> Also, I have experienced problems with the display on the developer build of
> linaro 12.07. Anyone else experience that? The monitor turns on and then off
> repeatedly after booting up every 10 seconds, with no signal. I have to do a
> cold reboot in order for it to work, and it works about 50% of the times.
>
> Thanks,
> John

[Rob Clark]

On Wed, Sep 12, 2012 at 11:32 AM, <swig...@googlemail.com> wrote:
> Thanks for the reply, but it doesn't seem to be working. I think I'm doing
> something wrong. It seems that it's using omapdrm, I also don't get the
> device names from the kernel messages:
> # dmesg | grep drm
> [ 4.181304] [drm] Initialized drm 1.1.0 20060810
> [ 6.649169] omapdrm omapdrm.0: dvi has no driver.. skipping it
> [ 7.312744] fb0: omapdrm frame buffer device
> [ 7.317413] drm: registered panic notifier
> [ 7.322021] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
> [ 7.329223] [drm] No driver support for vblank timestamp query.
> [ 7.335662] [drm] Initialized omapdrm 1.0.0 20110403 on minor 0
> # cat fb
> 0 omapdrm
>
> I tried modifying boot.txt with your example bootarg, so it looks like this
>
>> setenv initrd_high "0xffffffff"
>> setenv fdt_high "0xffffffff"
>> setenv bootcmd "fatload mmc 0:1 0x80200000 uImage; fatload mmc 0:1
>> 0x81600000 uInitrd; fatload mmc 0:1 0x815f0000 board.dtb; bootm 0x80200000
>> 0x81600000 0x815f0000"
>> setenv bootargs "console=tty0 console=ttyO2,115200n8
>> root=UUID=bbdbbbf2-53ac-46bd-a887-5893e74946ef rootwait ro earlyprintk
>> fixrtc nocompcache vram=48M omapfb.vram=0:24M video="HDMI Type A-1:800x600"
>> mem=456M@0x80000000 mem=512M@0xA$
>> boot
>
>
> after that,
>
> # mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n "Run uImage" -d
> boot.txt boot.scr
> Image Name: Run uImage
> Created: Wed Sep 12 12:20:52 2012
> Image Type: ARM Linux Script (uncompressed)
> Data Size: 486 Bytes = 0.47 kB = 0.00 MB
> Load Address: 00000000
> Entry Point: 00000000
> Contents:
> Image 0: 478 Bytes = 0.47 kB = 0.00 MB
> # chmod a+x boot.scr
> # reboot
>
> After rebooting the bootargs are displayed in the kernel messages but the
> resolution stays at 1280x1024.

Oh, that probably should have been video="HDMI-A-1:800x600" (or
DVI-D-1.. see /sys/class/drm)

BR,
-R

> I have also tried with these instead, same results:
> omapfb.video_mode=800x600MR-16@60
> video=omapfb:mode:800x600@60
>
> The distribution on which I'm trying these is a bit older than 12.07, as
> that had display issues that I thought might interfere with the mode
> settings:
> # lsb_release -a
> No LSB modules are available.
> Distributor ID: Linaro
> Description: Linaro 12.03
> Release: 12.03
> Codename: oneiric
> # uname -a
> Linux panda 3.1.1-29-linaro-lt-omap
> #29~lt~ci~20120328002449+1332949706~4f7349b0-Ubuntu SMP PREEMPT armv7l
> armv7l armv7l GNU/Linux
>
>
> John