Re: Hang after "BIOS data check successful" with DVI

Re: Hang after "BIOS data check successful" with DVI

[Petr Vandrovec]

On 16 Aug 04 at 16:55, Shaun Jackman wrote:
> When I have a DVI display plugged into my Matrox G550 video card the
> boot process hangs at "BIOS data check successful". I am running Linux
> kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
> boot without the DVI display plugged in, I can plug it in after the
> boot process and the display works.

Try disabling CONFIG_VIDEO_SELECT and/or comment out call to store_edid
in arch/i386/boot/video.S. Also which bootloader you use? From
quick glance at bootloaders, grub1 seems to set %sp to 0x9000, while 
LILO to 0x0800. And I think that 2048 byte stack (plus something already 
allocated by loader) might be too small for DDC call, as MGA BIOS first
creates EDID copy on stack...
                                           Best regards,
                                                Petr Vandrovec
                                                

Re: Hang after "BIOS data check successful" with DVI

[Zwane Mwaikambo]

On Tue, 17 Aug 2004, Petr Vandrovec wrote:

> On 16 Aug 04 at 16:55, Shaun Jackman wrote:
> > When I have a DVI display plugged into my Matrox G550 video card the
> > boot process hangs at "BIOS data check successful". I am running Linux
> > kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
> > boot without the DVI display plugged in, I can plug it in after the
> > boot process and the display works.
>
> Try disabling CONFIG_VIDEO_SELECT and/or comment out call to store_edid
> in arch/i386/boot/video.S. Also which bootloader you use? From
> quick glance at bootloaders, grub1 seems to set %sp to 0x9000, while
> LILO to 0x0800. And I think that 2048 byte stack (plus something already
> allocated by loader) might be too small for DDC call, as MGA BIOS first
> creates EDID copy on stack...

Urgh, this bug is still around :(

http://bugme.osdl.org/show_bug.cgi?id=1458

Re: Hang after "BIOS data check successful" with DVI

[Dave Jones]

On Tue, Aug 17, 2004 at 09:51:55AM -0400, Zwane Mwaikambo wrote:
 > On Tue, 17 Aug 2004, Petr Vandrovec wrote:
 > 
 > > On 16 Aug 04 at 16:55, Shaun Jackman wrote:
 > > > When I have a DVI display plugged into my Matrox G550 video card the
 > > > boot process hangs at "BIOS data check successful". I am running Linux
 > > > kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
 > > > boot without the DVI display plugged in, I can plug it in after the
 > > > boot process and the display works.
 > >
 > > Try disabling CONFIG_VIDEO_SELECT and/or comment out call to store_edid
 > > in arch/i386/boot/video.S. Also which bootloader you use? From
 > > quick glance at bootloaders, grub1 seems to set %sp to 0x9000, while
 > > LILO to 0x0800. And I think that 2048 byte stack (plus something already
 > > allocated by loader) might be too small for DDC call, as MGA BIOS first
 > > creates EDID copy on stack...
 > 
 > Urgh, this bug is still around :(
 > 
 > http://bugme.osdl.org/show_bug.cgi?id=1458

sidenote: A number of the int 10h calls in arch/i386/boot/video.S either
don't check the return code, and blindly assume everything went ok,
or do the wrong thing with them.

Example..

# get video mem size
    leaw    modelist+1024, %di
    movw    $0x4f00, %ax
    int $0x10
    xorl    %eax, %eax
    movw    18(%di), %ax
    movl    %eax, %fs:(PARAM_LFB_SIZE)

Checking http://www.ctyme.com/intr/rb-0273.htm shows that on return
from the int 10h, we should check al==4f before doing anything with
the results. Instead we not only ignore the return code, but trash it 8-)

Same story with function 4f0a a few lines below.

I did have a patch to change this a looong time ago (early 2.5)
but I don't know what became of it. Even google doesn't seem to turn it
up, so its possible I never got around to posting it.

		Dave

Re: Hang after "BIOS data check successful" with DVI

[Shaun Jackman]

On Tue August 17, 2004 03h57, Petr Vandrovec wrote:
> On 16 Aug 04 at 16:55, Shaun Jackman wrote:
> > When I have a DVI display plugged into my Matrox G550 video card the
> > boot process hangs at "BIOS data check successful". I am running Linux
> > kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
> > boot without the DVI display plugged in, I can plug it in after the
> > boot process and the display works.
> 
> Try disabling CONFIG_VIDEO_SELECT and/or comment out call to store_edid
> in arch/i386/boot/video.S. Also which bootloader you use? From
> quick glance at bootloaders, grub1 seems to set %sp to 0x9000, while 
> LILO to 0x0800. And I think that 2048 byte stack (plus something already 
> allocated by loader) might be too small for DDC call, as MGA BIOS first
> creates EDID copy on stack...
>                                            Best regards,
>                                                 Petr Vandrovec

I tried removing the call to store_edid and that does indeed fix my
problem!

Many thanks!
Shaun

Re: Hang after "BIOS data check successful" with DVI

[Shaun Jackman]

On Tue August 17, 2004 03h57, Petr Vandrovec wrote:
> On 16 Aug 04 at 16:55, Shaun Jackman wrote:
> > When I have a DVI display plugged into my Matrox G550 video card the
> > boot process hangs at "BIOS data check successful". I am running Linux
> > kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
> > boot without the DVI display plugged in, I can plug it in after the
> > boot process and the display works.
> 
> Try disabling CONFIG_VIDEO_SELECT and/or comment out call to store_edid
> in arch/i386/boot/video.S. Also which bootloader you use? From
> quick glance at bootloaders, grub1 seems to set %sp to 0x9000, while 
> LILO to 0x0800. And I think that 2048 byte stack (plus something already 
> allocated by loader) might be too small for DDC call, as MGA BIOS first
> creates EDID copy on stack...
>                                            Best regards,
>                                                 Petr Vandrovec

I'm using Lilo 22.5.9-2 from Debian.

Cheers,
Shaun

Re: Hang after "BIOS data check successful" with DVI

[Petr Vandrovec]

On 17 Aug 04 at 9:51, Zwane Mwaikambo wrote:
> On Tue, 17 Aug 2004, Petr Vandrovec wrote:
> 
> > On 16 Aug 04 at 16:55, Shaun Jackman wrote:
> > > When I have a DVI display plugged into my Matrox G550 video card the
> > > boot process hangs at "BIOS data check successful". I am running Linux
> > > kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
> > > boot without the DVI display plugged in, I can plug it in after the
> > > boot process and the display works.
> >
> > Try disabling CONFIG_VIDEO_SELECT and/or comment out call to store_edid
> > in arch/i386/boot/video.S. Also which bootloader you use? From
> > quick glance at bootloaders, grub1 seems to set %sp to 0x9000, while
> > LILO to 0x0800. And I think that 2048 byte stack (plus something already
> > allocated by loader) might be too small for DDC call, as MGA BIOS first
> > creates EDID copy on stack...
> 
> Urgh, this bug is still around :(
> 
> http://bugme.osdl.org/show_bug.cgi?id=1458

Yes, it looks like this very same problem. From looking at G400 BIOS
it would need 380 bytes plus whatever PCI BIOS services need - and PCI
BIOS system calls are specced to fit into 1024 bytes on stack. G550 BIOS
seems to need 200 bytes plus whatever PCI BIOS services need. So
LILO's 2KB should be sufficient - and indeed I do not see problem
with G550 & LILO (Debian's 22.5.9) here, with both DVI and analog cables 
connected in.
                                                Best regards,
                                                    Petr Vandrovec
                                                    

Hang after "BIOS data check successful" with DVI

[Shaun Jackman]

When I have a DVI display plugged into my Matrox G550 video card the
boot process hangs at "BIOS data check successful". I am running Linux
kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
boot without the DVI display plugged in, I can plug it in after the
boot process and the display works.

Please cc me in your reply. Thanks,
Shaun

Re: Hang after "BIOS data check successful" with DVI

[Aaron Michael Bauman]

[-- Attachment #1: Type: text/plain, Size: 861 bytes --]

On Mon, 2004-08-16 at 23:55, Shaun Jackman wrote:
> When I have a DVI display plugged into my Matrox G550 video card the
> boot process hangs at "BIOS data check successful". I am running Linux
> kernel 2.6.6. This problem does not affect Linux kernel 2.4.26. If I
> boot without the DVI display plugged in, I can plug it in after the
> boot process and the display works.
> 
> Please cc me in your reply. Thanks,
> Shaun

Shaun,
#kernel on freenode recommends that users running the 2.6.x tree to stay
at 2.6.7+, so try upgrading your kernel, stay above 2.6.7 and see what
happens. 
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]