Bug 11932

Summary: [intel] need to use BIOS modes or ACPI EDID in more cases
Product: xorg Reporter: Brice Goglin <brice.goglin>
Component: Driver/intelAssignee: Eric Anholt <eric>
Status: RESOLVED DUPLICATE QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium CC: anssi, bolmsted, remko, sndirsch, ynvich
Version: git   
Hardware: Other   
OS: All   
URL: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=437066
Whiteboard:
i915 platform: i915 features:
Bug Depends on:    
Bug Blocks: 13027    
Attachments:
Description Flags
patch to prefer bios_mode if HDisplay is 1366
none
patch fixes the problem for xorg v1.4.1 none

Description Brice Goglin 2007-08-10 09:58:53 UTC
Bug reported by Sergey Yanovich on the Debian BTS about a month ago (the Debian bug is kind of messy since it mixes 2 independent problems).

He's using a Sony VGN-TX770 notebook with a wide 1366x768 panel. The old i810 driver got 1366x768 correctly.

Intel driver 2.1.0 and git snapshot from today (2007/08/10) both fail to detect the correct panel size. They only get 1024x768 and thus refuse any mode with a larger resolution. ModeLine+PreferredMode didn't help.

His current xorg.conf is available at:
http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=141;filename=xorg.conf;att=2;bug=437066

The Xorg.0.log with git snapshot from today is available:
http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=141;filename=Xorg.0.log;att=1;bug=437066

Note that the "i830_lvds_mode_valid: Using panel dimensions 1024x768" lines come from a debugging patch that I asked him to apply so that we knew the detected panel size. It doesn't break anything :)
Comment 1 Wang Zhenyu 2007-08-29 09:29:32 UTC
maybe we should only make panel probed mode as preferred if it's really got from DDC. Then assign panel mode from bios to probed mode that's not preferred, like got enabled in 1024x768 console text mode.
Comment 2 Remko Bolt 2007-09-05 05:08:25 UTC
I own a Sony VGN-T2XP (which I believe is the previous model) with a 82852/855GM and experience similar problems (driver only displays 1024x768 i.s.o. 1280x768). 

Following instructions from https://bugs.freedesktop.org/show_bug.cgi?id=2417 I installed http://www.fairlite.demon.co.uk/i810_drv.so and it works in combination with 915resolution.

I'm not sure if it is related, but if there is anything I can do to help please let me know.
Comment 3 Sergey Yanovich 2007-09-20 14:44:11 UTC
Created attachment 11663 [details] [review]
patch to prefer bios_mode if HDisplay is 1366

This is little straight-forward, but it completely restores intel driver functionality on my VGN-TX770P.

My old driver is no longer supported by debian/unstable. The new driver is way better than the old, by the way.
Comment 4 Brice Goglin 2007-10-03 10:10:43 UTC
Looks like James R. Van Zandt has a similar problem on a Sony Vaio VGN-TXN27N, with an Intel 945GM chipset and a 1366x768 LVDS. It gets 800x600 instead.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=445067

Comment 5 Pierre Mazière 2007-10-04 03:59:21 UTC
(In reply to comment #3)
This patch was the perfect solution for my Sony Vaio T2XP (855GM and 1280x768 LVDS): I just had to replace all the 1366 value by 1280.
I guess that if this value is replaced in the code by the width of the mode passed to the driver from the xorg.conf file, then it could be included in the main repository as a generic fix for specific resolution found on various LVDS.

Comment 6 Sergey Yanovich 2007-10-04 04:14:41 UTC
wang:
(In reply to comment #1)
> maybe we should only make panel probed mode as preferred if it's really got
> from DDC. Then assign panel mode from bios to probed mode that's not preferred,
> like got enabled in 1024x768 console text mode.

i have only now got the point. my patch does exactly this.
Comment 7 Sergey Yanovich 2007-10-04 04:21:48 UTC
brice:

(In reply to comment #4)
> Looks like James R. Van Zandt has a similar problem on a Sony Vaio VGN-TXN27N,
> with an Intel 945GM chipset and a 1366x768 LVDS. It gets 800x600 instead.

Looks like sony doesn't care to implement ddc in its laptops. Bios modes are fine though. If you (or anyone else) can point me to a resource, which explains how Xorg preferences can be accessed, I can add "SupressDDCProbe" option.
Comment 8 Michael Fu 2007-10-31 17:42:06 UTC

*** This bug has been marked as a duplicate of bug 11917 ***
Comment 9 Sergey Yanovich 2007-11-27 07:43:34 UTC
Created attachment 12741 [details] [review]
patch fixes the problem for xorg v1.4.1

Previous patch is failing with 1.4.1 server.

New patch copies DisplayMode structure, the old one was adding a new.
Comment 10 Michael Fu 2007-12-25 00:20:32 UTC
*** Bug 12025 has been marked as a duplicate of this bug. ***
Comment 11 Sergey Yanovich 2007-12-26 15:27:49 UTC
I have accidentally found an easy workaround.

In my case the problem is caused by 'vga=791' kernel parameter. Removing the parameter makes unpatched driver behave properly.

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