frame buffer compression and 915GM

frame buffer compression and 915GM

[SD]

Dear All.

How can I find out if FBC is disabled/enabled for my i915GM on kernel 2.6.38.6-27 and on rawhide 2.6.39-1.

Thanks

Re: frame buffer compression and 915GM

[Ben Widawsky]

On Thu, May 26, 2011 at 12:29:07PM -0700, SD wrote:
> Dear All.
> 
> How can I find out if FBC is disabled/enabled for my i915GM on kernel 2.6.38.6-27 and on rawhide 2.6.39-1.
> 
> Thanks

debugfs has it. For example:
cat /sys/kernel/debug/dri/0/i915_fbc_status

Ben

Re: frame buffer compression and 915GM

[SD]

OK, thank you. I checked it, and I got unexpected answer -

FBC unsupported on this chipset.


But on my old OpenSuse:

X.Org X Server 1.5.2
Release Date: 10 October 2008
X Protocol Version 11, Revision 0
Build Operating System: openSUSE SUSE LINUX
Current Operating System: Linux linux-xmc2 2.6.27.45-0.1-pae #1 SMP 2010-02-22 16:49:47 +0100 i686
Build Date: 22 September 2010  11:23:20AM
...

(**) intel(0): Option "FramebufferCompression" "on"
...
(**) intel(0): Framebuffer compression enabled
...

As you can see - It was supported 3 years ago.

I would like to know why now FBC becomes unsupported ?

Thank you.

Re: frame buffer compression and 915GM

[Clemens Eisserer]

I also get "FBC unsupported on this chipset" with 2.6.38.6 on i945GM,
although I can remember it used to work a year ago or so.
Have there been some correctness checks that disable it on hardware
known to be bugged?

Thanks, Clemens

2011/5/27 SD <sd.domrep@yahoo.com>:
> OK, thank you. I checked it, and I got unexpected answer -
>
> FBC unsupported on this chipset.
>
>
> But on my old OpenSuse:
>
> X.Org X Server 1.5.2
> Release Date: 10 October 2008
> X Protocol Version 11, Revision 0
> Build Operating System: openSUSE SUSE LINUX
> Current Operating System: Linux linux-xmc2 2.6.27.45-0.1-pae #1 SMP 2010-02-22 16:49:47 +0100 i686
> Build Date: 22 September 2010  11:23:20AM
> ...
>
> (**) intel(0): Option "FramebufferCompression" "on"
> ...
> (**) intel(0): Framebuffer compression enabled
> ...
>
> As you can see - It was supported 3 years ago.
>
> I would like to know why now FBC becomes unsupported ?
>
> Thank you.
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: frame buffer compression and 915GM

[SD]

--- On Fri, 5/27/11, Clemens Eisserer <linuxhippy@gmail.com> wrote:

> From: Clemens Eisserer <linuxhippy@gmail.com>
> Subject: Re: [Intel-gfx] frame buffer compression and 915GM
> To: "intel-gfx" <intel-gfx@lists.freedesktop.org>
> Date: Friday, May 27, 2011, 6:50 PM
> I also get "FBC unsupported on this
> chipset" with 2.6.38.6 on i945GM,
> although I can remember it used to work a year ago or so.
> Have there been some correctness checks that disable it on
> hardware
> known to be bugged?
> 
> Thanks, Clemens



Unsupported, disabled, enabled are different things.

If FBC supported it can be disabled/enabled.

If it is unsupported it means that something is wrong with detection, because second OS on the same laptop - 3 years old OpenSuse uses it without problems.

Thank you.







> 
> 2011/5/27 SD <sd.domrep@yahoo.com>:
> > OK, thank you. I checked it, and I got unexpected
> answer -
> >
> > FBC unsupported on this chipset.
> >
> >
> > But on my old OpenSuse:
> >
> > X.Org X Server 1.5.2
> > Release Date: 10 October 2008
> > X Protocol Version 11, Revision 0
> > Build Operating System: openSUSE SUSE LINUX
> > Current Operating System: Linux linux-xmc2
> 2.6.27.45-0.1-pae #1 SMP 2010-02-22 16:49:47 +0100 i686
> > Build Date: 22 September 2010  11:23:20AM
> > ...
> >
> > (**) intel(0): Option "FramebufferCompression" "on"
> > ...
> > (**) intel(0): Framebuffer compression enabled
> > ...
> >
> > As you can see - It was supported 3 years ago.
> >
> > I would like to know why now FBC becomes unsupported
> ?
> >
> > Thank you.
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 

Re: frame buffer compression and 915GM

[Ben Widawsky]

On Fri, May 27, 2011 at 01:51:53AM -0700, SD wrote:
> OK, thank you. I checked it, and I got unexpected answer -
> 
> FBC unsupported on this chipset.

I'd need to know exactly which chipset you have. For example. Ironlake
mobile, we disabled FBC because it was actually consuming more power.

You can check your specific chipset, and look at the has_fbc field here:
drivers/gpu/drm/i915/i915_drv.c

Ben

Re: frame buffer compression and 915GM

[SD]

--- On Fri, 5/27/11, Ben Widawsky <ben@bwidawsk.net> wrote:

> From: Ben Widawsky <ben@bwidawsk.net>
> Subject: Re: [Intel-gfx] frame buffer compression and 915GM
> To: "SD" <sd.domrep@yahoo.com>
> Cc: intel-gfx@lists.freedesktop.org
> Date: Friday, May 27, 2011, 11:48 PM
> On Fri, May 27, 2011 at 01:51:53AM
> -0700, SD wrote:
> > OK, thank you. I checked it, and I got unexpected
> answer -
> > 
> > FBC unsupported on this chipset.
> 
> I'd need to know exactly which chipset you have. For
> example. Ironlake
> mobile, we disabled FBC because it was actually consuming
> more power.
> 
> You can check your specific chipset, and look at the
> has_fbc field here:
> drivers/gpu/drm/i915/i915_drv.c
> 
> Ben
> 

Thanks.
I checked it out.
You threw FBC from i915_drv since 2.6.33, because in 2.6.32 there was not any sign of pci_id detection. And since then I got awful screen picture quality, because I start to test with Fedora 12 and then jumped to Fedora 13 with 33 kernel, and since then never had normal picture - always flickers.

I know you are all very clever here and are thinking about some Watts, but I am, like a user, thinking about my eyes first and want to tell you that you did mistake.
May be FBC uses more power (I am not sure about it, as long 3D performance on i915gm is "nothing" anyway), but it looks like FBC helps to produce nice and smooth picture on laptop LSD.

My card id:
[    0.100352] pci 0000:00:02.0: [8086:2592] type 0 class 0x000300
[    0.100431] pci 0000:00:02.1: [8086:2792] type 0 class 0x000380

and I would like to have ability to ENABLE FBC in rawhide or in Fedora 15.
Do you know why? Because I want to use Fedora, but still can't.



P. S.
Sorry about all above, if an awful picture on my i915gm has not any relation to FBC.

Re: frame buffer compression and 915GM

[Ben Widawsky]

On Sat, May 28, 2011 at 01:50:12AM -0700, SD wrote:
> 
> 
> --- On Fri, 5/27/11, Ben Widawsky <ben@bwidawsk.net> wrote:
> 
> > From: Ben Widawsky <ben@bwidawsk.net>
> > Subject: Re: [Intel-gfx] frame buffer compression and 915GM
> > To: "SD" <sd.domrep@yahoo.com>
> > Cc: intel-gfx@lists.freedesktop.org
> > Date: Friday, May 27, 2011, 11:48 PM
> > On Fri, May 27, 2011 at 01:51:53AM
> > -0700, SD wrote:
> > > OK, thank you. I checked it, and I got unexpected
> > answer -
> > > 
> > > FBC unsupported on this chipset.
> > 
> > I'd need to know exactly which chipset you have. For
> > example. Ironlake
> > mobile, we disabled FBC because it was actually consuming
> > more power.
> > 
> > You can check your specific chipset, and look at the
> > has_fbc field here:
> > drivers/gpu/drm/i915/i915_drv.c
> > 
> > Ben
> > 
> 
> Thanks.
> I checked it out.
> You threw FBC from i915_drv since 2.6.33, because in 2.6.32 there was not any sign of pci_id detection. And since then I got awful screen picture quality, because I start to test with Fedora 12 and then jumped to Fedora 13 with 33 kernel, and since then never had normal picture - always flickers.
> 
> I know you are all very clever here and are thinking about some Watts, but I am, like a user, thinking about my eyes first and want to tell you that you did mistake.
> May be FBC uses more power (I am not sure about it, as long 3D performance on i915gm is "nothing" anyway), but it looks like FBC helps to produce nice and smooth picture on laptop LSD.

I don't think FBC should have any positive impact on the display, but I
suppose that is a subjective thing.

You should see Jesse's commit in keithp's drm-intel-next
(c1a9f047638b27e481d097910604316b8a0d132b). If you're capable of writing
code, I'd suggest you do the same thing for intel_i915gm_info where fbc
can be enabled, but is off by default. If not, hopefully I, or someone
else will get around to it eventually.

Ben

Re: frame buffer compression and 915GM

[SD]

--- On Sun, 5/29/11, Ben Widawsky <ben@bwidawsk.net> wrote:

> From: Ben Widawsky <ben@bwidawsk.net>
> Subject: Re: [Intel-gfx] frame buffer compression and 915GM
> To: "SD" <sd.domrep@yahoo.com>
> Cc: intel-gfx@lists.freedesktop.org
> Date: Sunday, May 29, 2011, 2:47 AM
> On Sat, May 28, 2011 at 01:50:12AM
> -0700, SD wrote:
> > 
> > 
> > --- On Fri, 5/27/11, Ben Widawsky <ben@bwidawsk.net>
> wrote:
> > 
> > > From: Ben Widawsky <ben@bwidawsk.net>
> > > Subject: Re: [Intel-gfx] frame buffer compression
> and 915GM
> > > To: "SD" <sd.domrep@yahoo.com>
> > > Cc: intel-gfx@lists.freedesktop.org
> > > Date: Friday, May 27, 2011, 11:48 PM
> > > On Fri, May 27, 2011 at 01:51:53AM
> > > -0700, SD wrote:
> > > > OK, thank you. I checked it, and I got
> unexpected
> > > answer -
> > > > 
> > > > FBC unsupported on this chipset.
> > > 
> > > I'd need to know exactly which chipset you have.
> For
> > > example. Ironlake
> > > mobile, we disabled FBC because it was actually
> consuming
> > > more power.
> > > 
> > > You can check your specific chipset, and look at
> the
> > > has_fbc field here:
> > > drivers/gpu/drm/i915/i915_drv.c
> > > 
> > > Ben
> > > 
> > 
> > Thanks.
> > I checked it out.
> > You threw FBC from i915_drv since 2.6.33, because in
> 2.6.32 there was not any sign of pci_id detection. And since
> then I got awful screen picture quality, because I start to
> test with Fedora 12 and then jumped to Fedora 13 with 33
> kernel, and since then never had normal picture - always
> flickers.
> > 
> > I know you are all very clever here and are thinking
> about some Watts, but I am, like a user, thinking about my
> eyes first and want to tell you that you did mistake.
> > May be FBC uses more power (I am not sure about it, as
> long 3D performance on i915gm is "nothing" anyway), but it
> looks like FBC helps to produce nice and smooth picture on
> laptop LSD.
> 
> I don't think FBC should have any positive impact on the
> display, but I
> suppose that is a subjective thing.
> 
> You should see Jesse's commit in keithp's drm-intel-next
> (c1a9f047638b27e481d097910604316b8a0d132b). If you're
> capable of writing
> code, I'd suggest you do the same thing for
> intel_i915gm_info where fbc
> can be enabled, but is off by default. If not, hopefully I,
> or someone
> else will get around to it eventually.
> 
> Ben
> 



Actually, I prefer if some of you can add module parameter to control FBC from the kernel command line, as it was popped up somewhere about 2.6.40 and, which is more important, was previously in xorg.conf as - Option "FramebufferCompression" "boolean"
Module parameter for grub would be the best way, because as long as you can't test video output thoughtfully by yourself, let allow users to decide.

But, to be able to enable FBC, I suppose 

My card id:
[    0.100352] pci 0000:00:02.0: [8086:2592] type 0 class 0x000300
[    0.100431] pci 0000:00:02.1: [8086:2792] type 0 class 0x000380


those:

static const struct intel_device_info intel_i945g_info = {
         .gen = 3, .has_hotplug = 1, .cursor_needs_physical = 1,
         .has_overlay = 1, .overlay_needs_physical = 1,
 };
 static const struct intel_device_info intel_i945gm_info = {
         .gen = 3, .is_i945gm = 1, .is_mobile = 1,
         .has_hotplug = 1, .cursor_needs_physical = 1,
         .has_overlay = 1, .overlay_needs_physical = 1,
         .supports_tv = 1,
 };

should have at least: ".has_fbc = 1/0" as initial state, otherwise it always will be unsupported.


And please, do it yourself, as it is still yours responsibility. I am just unhappy user.


Sincerely.