psb_gfx removal

psb_gfx removal

[Jan Engelhardt]

Hi,


I have here a "Wortmann AG terra Pad 1051", which has a GMA500-like 
device (PCI ID 8086:4102). Using Linux 3.1.x (openSUSE 12.1's default), 
loading psb_gfx.ko crashed the machine. I therefore tried Linux 3.4.0,
where this crash does not occur thankfully.

According to your commit b7cdd9e6323af368e26121c5b791eddc78e79fea, 
GMA500 is now available through the DRM tree. I take it you mean 
kernel/drivers/gpu/drm/gma500/gma500_gfx.ko by that. However, 
gma500_gfx.ko does not provide support for 8086:4102, i.e. modinfo does 
not show the alias.

So, am I correct in the assumption that the 4102 code never really 
worked, and deletion of psb_gfx was therefore ok without having 4102 
support in gma500_gfx?


thanks,
Jan

Re: psb_gfx removal

[Alan Cox]

On Tue, 5 Jun 2012 14:51:54 +0200 (CEST)
Jan Engelhardt <jengelh@inai.de> wrote:

> Hi,
> 
> 
> I have here a "Wortmann AG terra Pad 1051", which has a GMA500-like 
> device (PCI ID 8086:4102). Using Linux 3.1.x (openSUSE 12.1's default), 
> loading psb_gfx.ko crashed the machine. I therefore tried Linux 3.4.0,
> where this crash does not occur thankfully.
> 
> According to your commit b7cdd9e6323af368e26121c5b791eddc78e79fea, 
> GMA500 is now available through the DRM tree. I take it you mean 
> kernel/drivers/gpu/drm/gma500/gma500_gfx.ko by that. However, 
> gma500_gfx.ko does not provide support for 8086:4102, i.e. modinfo does 
> not show the alias.
> 
> So, am I correct in the assumption that the 4102 code never really 
> worked, and deletion of psb_gfx was therefore ok without having 4102 
> support in gma500_gfx?

0x4102 is an Oaktrail device (GMA600). The driver supports it providing
you have the GMA600 option set.

Alan

Re: psb_gfx removal

[Greg KH]

On Tue, Jun 05, 2012 at 03:01:06PM +0200, Jan Engelhardt wrote:
> [fixed up gregkh's address]
> 
> Hi,
> 
> 
> I have here a "Wortmann AG terra Pad 1051", which has a GMA500-like 
> device (PCI ID 8086:4102). Using Linux 3.1.x (openSUSE 12.1's default), 
> loading psb_gfx.ko crashed the machine. I therefore tried Linux 3.4.0,
> where this crash does not occur thankfully.
> 
> According to your commit b7cdd9e6323af368e26121c5b791eddc78e79fea, 
> GMA500 is now available through the DRM tree. I take it you mean 
> kernel/drivers/gpu/drm/gma500/gma500_gfx.ko by that. However, 
> gma500_gfx.ko does not provide support for 8086:4102, i.e. modinfo does 
> not show the alias.
> 
> So, am I correct in the assumption that the 4102 code never really 
> worked, and deletion of psb_gfx was therefore ok without having 4102 
> support in gma500_gfx?

I have no idea at all, that would be up to Alan to answer, not me.

greg k-h

Re: psb_gfx removal

[Jan Engelhardt]

On Tuesday 2012-06-05 18:29, Alan Cox wrote:
>> 
>> [Wortmann AG's terra Pad 1051, with a 8086:4102 display chip]
>
>0x4102 is an Oaktrail device (GMA600). The driver supports it providing
>you have the GMA600 option set.

Thanks for the info. Setting GMA600=y works, as in, it results
in graphical mode on tty1.

However, the gma600 driver seems to default to a backlight value of
"0" in Linux 3.4.1; getting a dark screen after loading gma500_gfx.ko 
is rather unexpected.

Furthermore, there are four entries in sysfs, and the one required to
change the panel brightness is acpi_video2 (and this one alone).
Changing any others, e.g. acpi_video0/brightness, does not have any
visible effect.

linux-kisn:/sys/class/backlight # ls -l
total 0
lrwxrwxrwx 1 root root 0 Jun  7 17:31 acpi_video0 -> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video0
lrwxrwxrwx 1 root root 0 Jun  7 17:31 acpi_video1 -> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video1
lrwxrwxrwx 1 root root 0 Jun  7 17:31 acpi_video2 -> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video2
lrwxrwxrwx 1 root root 0 Jun  7 17:31 oaktrail-bl -> ../../devices/virtual/backlight/oaktrail-bl

Re: psb_gfx removal

[Alan Cox]

On Thu, 7 Jun 2012 15:53:43 +0200 (CEST)
Jan Engelhardt <jengelh@inai.de> wrote:

> On Tuesday 2012-06-05 18:29, Alan Cox wrote:
> >> 
> >> [Wortmann AG's terra Pad 1051, with a 8086:4102 display chip]
> >
> >0x4102 is an Oaktrail device (GMA600). The driver supports it
> >providing you have the GMA600 option set.
> 
> Thanks for the info. Setting GMA600=y works, as in, it results
> in graphical mode on tty1.
> 
> However, the gma600 driver seems to default to a backlight value of
> "0" in Linux 3.4.1; getting a dark screen after loading gma500_gfx.ko 
> is rather unexpected.

The ACPI and GMA code fall out over the backlight somewhat. I had hoped
to fix it in 3.5-rc but Linus threw out all the ACPI tree changes.

Disable ACPI video in your configuration and see if it behaves
properly. If not then it will need chasing down in more detail.

Alan