Bug 20752

Summary:	[KMS] radeon not working reliable with X1300
Product:	Drivers	Reporter:	Torsten Krah (krah.tm)
Component:	Video(DRI - non Intel)	Assignee:	drivers_video-dri
Status:	RESOLVED OBSOLETE
Severity:	normal	CC:	alan, alexdeucher
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.38	Subsystem:
Regression:	No	Bisected commit-id:

Description Torsten Krah 2010-10-19 08:12:04 UTC

Hi,

got a 

01:00.0 VGA compatible controller: ATI Technologies Inc RV516 [Radeon X1300/X1550 Series]

card and tried to use KMS and radeon since its in the mainline tree but got no luck yet.
Resolution change does work and X is working too but there are some "bugs" which makes it unusable.

1. Console/Screen does blank from time to time - i can switch to first tty and wait and seeing the screen going blank for seconds and reappearing few seconds later. It does this a few times per minute.
Using X it appears to be not that often but still happening.
2. In X Screen does have some black lines running over the screen every time - reading some text on white background is really hard because of these black lines running through the screen everytime, hope you know what i mean - can't make a screenshot - this may not be related to KMS at all and i have to talk to Xorg guys for this error - please tell me - don't know where to report this one best.

The only configuration which is usable in terms of you can do your work >1 hour is to disable KMS and using the "old" radeonhd Xorg driver - which does work fine and without those "glitches".
Any help or information i can provide to make radeon "work" like radeonhd?

Comment 1 Torsten Krah 2010-10-19 08:27:53 UTC

Additional info, graphics chip is an RV516:

[ 59807.498] (II) RADEONHD(0): Card not in database: 0x7187:0x1028:0x0402; using generic modesetting.
[ 59807.498] (--) RADEONHD(0): Detected an RV516 on an unidentified card

Comment 2 Alex Deucher 2010-10-19 15:46:15 UTC

Does booting with radeon.new_pll=0 on your kernel command line help?  Additionally, can you try Dave's drm-next branch?  It has some other pll changes.
http://git.kernel.org/?p=linux/kernel/git/airlied/drm-2.6.git;a=shortlog;h=refs/heads/drm-next

Comment 3 Alex Deucher 2010-10-19 20:58:25 UTC

Another thing to try assuming this is a digital monitor (DVI or HDMI):
xrandr --output <output> --set coherent 0

Comment 4 Torsten Krah 2010-10-20 09:00:59 UTC

Thanks Alex for those hints.
radeon.new_pll=0 makes the first problem go away, no screen blanking anymore yet.
The second one is still there - not that often as before the adding the pll boot parameter but still there.
Using your second hint with xrandr --output DVI-0 --set coherent 0 seems to help with this, no more black lines on my screen. Nice.

I'll report again in one or two days of working if the problems are really gone - but the first impression looks promising - using both, new_pll=0 and xrandr coherent = 0 seems to make things work.

Comment 5 Torsten Krah 2010-10-22 13:02:23 UTC

Till now all is working, guess this is gone with those 2 workarounds. Thanks.

Comment 6 Alex Deucher 2010-10-22 15:30:32 UTC

The old pll code will be the default in 2.6.37, so in 2.6.37, you'll just need to adjust the coherent option.

Comment 7 Torsten Krah 2011-04-06 10:55:40 UTC

Is there any way to get KMS working without X?
Without the coherent option my screen blanks on/off - i cant work with it.
I need to run X and hava to issue (via xdg autostart e.g.) the xrandr command to be able to work.
Using only the console is not possible - any hint here? Is there a KMS option which does the same?

Comment 8 Alex Deucher 2011-04-06 14:36:25 UTC

(In reply to comment #7)
> Is there any way to get KMS working without X?

Are things working any better with 2.6.38?

> Without the coherent option my screen blanks on/off - i cant work with it.
> I need to run X and hava to issue (via xdg autostart e.g.) the xrandr command
> to be able to work.
> Using only the console is not possible - any hint here? Is there a KMS option
> which does the same?

No one has written a sysfs interface to change connector attributes yet.  It would be useful though.  Another alternative would be to write a command line app that uses the same ioctls X uses to change the attributes.

Comment 9 Torsten Krah 2011-04-06 18:21:51 UTC

I am using 2.6.38.2 (2.6.38-7 natty build) and things does not work better - monitor still blanks all the time around until coherent is set.

Oh i guess its beyond my "skills" to write such a command line app :-| or export those attributes to sysfs - although it would be nice to have either one of those options.