Distribution: SUSE 9.1 Professional Hardware Environment: Tyan S2460 board and Matrox G450 DH Software Environment: Immediately after load with GRUB or LILO Problem Description: With Linux 2.6.x kernels, option 'Video Mode Selection Support' causes a 2 minute delay with blank screen from kernel load via bootloader to appearance of any text on console Steps to reproduce: Linux kernel 2.6.x, compiled with 'Video Mode Selection Support' option, Tyan S2460 board and Matrox G450 DH. My Writeup: Problem: ======== With Linux 2.6.x kernels, option 'Video Mode Selection Support' causes a 2 minute delay with blank screen from kernel load via bootloader to appearance of any text on console Hardware: ========= Matrox g450, Tyan S2460 Essential Combination for fault: ================================ Linux kernel 2.6.x, compiled with 'Video Mode Selection Support' option, Tyan S2460 board and Matrox G450 DH. This combination with any one of the following changes does not give the fault: *** Kernel compiled without 'Video Mode Selection Support' option *** Kernel 2.4.x *** Different graphics card type [Videologic] *** Different mainboard Other notes: ============ May relate to report 1858, but filed separately as I think I am giving a lot more specifics and I will leave others to judge whether to make the link. Problem occurs with 2 examples of Matrox G450 card. First observed with SUSE kernel 2.6.4-54.5-default from version 9.1 profesional. Repeatable with various kernel.org 2.6.x kernels. Repeatable from SUSE 9.1 bootable DVD [delay here is 4 minutes]. Compilation change was applied only to SUSE kernel, and was only change necessary for a fix AFAICT. Only tried different mainboard with SUSE kernel from bootable DVD. A similar fault is discussed here: http://forums.whirlpool.net.au/forum-replies.cfm?t=196564&p=-1 I originally raised this issue here: http://lists.suse.de/archive/suse-linux-e/2004-May/1573.html
Is this issue still present in recent 2.6 kernels?
Adrian Bunk 2006-02-21 09:31: "Is this issue still present in recent 2.6 kernels?" Yes, exactly as described. My latest is vmlinuz-2.6.13-15.8-default from SuSE professional v10, and online updates. The work around - compile kernel without 'Video Mode Selection Support' [CONFIG_VIDEO_SELECT in make menuconfig] option - still works. I now also apply CONFIG_FB_MATROX_G from make menuconfig, which allows me to start up with video=matroxfb:vesa:0x1bf,left:320 and have a good resolution text screen, plus a Tux graphic, and no bootup delay. I have 3 other machines with the same graphics card and can use the standard SuSE kernel without recompiling and no problems. It is only the Tyan S2460 which has problems.
This is most probably an issue when doing Video BIOS DDC transfers. Cards that do DDC1 experience significant delays. Can you confirm? Comment out 'call store_edid' in arch/i386/boot/video.S. If you can confirm, I'll make this a config option and default to 'n' for matrox.
Yes that did it! Steps taken: 1] with menuconfig, unset CONFIG_FB_MATROX and CONFIG_FB_MATROX_G, set CONFIG_VIDEO_SELECT. Recompiled. Booted. Problem reproduced [4 minute wait to boot]. 2] Commented out 'call store_edid' in arch/i386/boot/video.S, as requested. Recompiled. Booted. Immediate boot. Trust that is OK and you are confident with my reporting.
Yes. I already sent a patch for the mm tree that makes EDID reading from the firmware a configurable option.
BTW, I just sent a patch for the mm tree. It will, hopefully, get to mainline but after 2.6.16. Once it's in mainline, an additional option under Graphics Device will appear, "Enable firmware EDID". Just set this to N to prevent the boot delay.