Bug 39216

Created attachment 49069 [details] [review]
LVDS panels are digital as well!

Another patch that slipped through the cracks...

Created attachment 49112 [details]
boot info with patch

Created attachment 49113 [details]
after done testdisplay info with patch

Created attachment 49114 [details]
dump info with testdisplay -i

(In reply to comment #1)
> Created an attachment (id=49069) [details]
> LVDS panels are digital as well!
> 
> Another patch that slipped through the cracks...

Hello Chris.I have tried your patch. Sometimes(sometimes SDVO_LVDS can't be lighted and backlight is off except I powoff the machine for a while) the SDVO_LVDS can work well with your patch. after I have done the preferred mode testing  with testdisplay command  in the console ,  the backlight is off , SDVO_LVDS can't be lighted ,but testdisplay can detect the SDVO_LVDS info. 
Attachment is the dmesg info

Right the patch fixes a false negative for detection, but it sounds like we have the usual testdisplay issues.

I guess testdisplay needs backlight support?  If you modify the backlight by directly echoing values into /sys/class/backlight/.../brightness do things work?

(In reply to comment #7)
> I guess testdisplay needs backlight support?  If you modify the backlight by
> directly echoing values into /sys/class/backlight/.../brightness do things
> work?

hello Jesse. There is nothing in /sys/class/backlight when it is just using SDVO_LVDS port

Kernel: (drm-intel-fixes)d7d39e20cc5e44f915d6c5687f65839632c44381
Some additional commit info:
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Wed Aug 3 12:59:21 2011 -0700

    drm/i915: enable/disable spread spectrum as needed on mode set

this issue also exists in this commit

Hi guys,

As I get it, the patch did not completely fix the problem. From a distribution side (Chakra), I'd like to ask the following:
- In which repository / branch are the patches?
- Does the last comment mean this code has the same problem or fixes it?
- If it's solved (it obviously isn't, our users still report this in our latest testing release with 3.0.4), will we see a backport to intel-fixes "for linus" or do we have to do that on our own or wait for 3.1?
- Are there any traces needed we could ask our users for if it's reported (I don't have a backlight-lid display to test it myself, sorry).

For the workaround (setpci -s 00:02.0 f4.b=00)
Do we have any chance to "check" system-side if this problem exists for the specified card? We could just add a rc-file as workaround if necessary from the distribution side.

Keith finally sent the patch upstream in

commit 2cfab8d74ebfbe06ce2947117945c4f45a5915ec
Merge: 5885b9b 3b5c78a
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri Dec 16 11:27:56 2011 -0800

    Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~keithp/linux

a mere 6 months after being sent the regression fix. This should fix the original problem, anything that remains (such as misconfigured ACPI) should be addressed elsewhere.

(In reply to comment #11)
> Keith finally sent the patch upstream in
> 
> commit 2cfab8d74ebfbe06ce2947117945c4f45a5915ec
> Merge: 5885b9b 3b5c78a
> Author: Linus Torvalds <torvalds@linux-foundation.org>
> Date:   Fri Dec 16 11:27:56 2011 -0800
> 
>     Merge branch 'drm-intel-fixes' of
> git://people.freedesktop.org/~keithp/linux
> 
> a mere 6 months after being sent the regression fix. This should fix the
> original problem, anything that remains (such as misconfigured ACPI) should be
> addressed elsewhere.


Hello. This patch has fixed the issue.
Tested-by: Wang Bo <bo.b.wang@intel.com>

A patch referencing this bug report has been merged in Linux v3.2-rc6:

commit 522200858093a6f31af9830672109f6d9807dd1e
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Jun 20 14:45:50 2011 +0100

    drm/i915/sdvo: Include LVDS panels for the IS_DIGITAL check

Closing old verified+fixed.