2010-11-10 07:11:13

by Johannes Hirte

[permalink] [raw]
Subject: [bisected] i915 regression in post 2.6.36 kernels

With the latest kernel, I don't get any windows in KDE displayed. After
starting kdm, I get the background picture and the mouse cursor but not the
login window. I can login blindly and a ps on console shows me that the
expected KDE processes are started but still nothing is displayed.
I've bisected this to:

5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad commit
commit 5c12a07e8073295ce8b57a822f811ac34e4f8420
Author: Chris Wilson <[email protected]>
Date: Wed Sep 22 11:22:30 2010 +0100

drm/i915: Drop ring->lazy_request

We are not currently using it as intended, so remove the complication.

Signed-off-by: Chris Wilson <[email protected]>


hardware is a Gigabyte M912 with

00:00.0 Host bridge: Intel Corporation Mobile 945GME Express Memory Controller Hub (rev 03)
Subsystem: Giga-byte Technology Device 1999
Flags: bus master, fast devsel, latency 0
Capabilities: [e0] Vendor Specific Information: Len=09 <?>
Kernel driver in use: agpgart-intel

00:02.0 VGA compatible controller: Intel Corporation Mobile 945GME Express Integrated Graphics Controller (rev 03) (prog-if 00 [VGA controller])
Subsystem: Giga-byte Technology Device 1999
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at f2200000 (32-bit, non-prefetchable) [size=512K]
I/O ports at 18d0 [size=8]
Memory at d0000000 (32-bit, prefetchable) [size=256M]
Memory at f2300000 (32-bit, non-prefetchable) [size=256K]
Expansion ROM at <unassigned> [disabled]
Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Kernel driver in use: i915

00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)
Subsystem: Giga-byte Technology Device 1999
Flags: bus master, fast devsel, latency 0
Memory at f2280000 (32-bit, non-prefetchable) [disabled] [size=512K]
Capabilities: [d0] Power Management version 2


regards,
Johannes


2010-11-10 07:46:44

by Chris Wilson

[permalink] [raw]
Subject: Re: [bisected] i915 regression in post 2.6.36 kernels

On Wed, 10 Nov 2010 08:02:19 +0100, Johannes Hirte <[email protected]> wrote:
> With the latest kernel, I don't get any windows in KDE displayed. After
> starting kdm, I get the background picture and the mouse cursor but not the
> login window. I can login blindly and a ps on console shows me that the
> expected KDE processes are started but still nothing is displayed.
> I've bisected this to:
>
> 5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad commit
> commit 5c12a07e8073295ce8b57a822f811ac34e4f8420
> Author: Chris Wilson <[email protected]>
> Date: Wed Sep 22 11:22:30 2010 +0100
>
> drm/i915: Drop ring->lazy_request
>
> We are not currently using it as intended, so remove the complication.
>
> Signed-off-by: Chris Wilson <[email protected]>

May I ask you to recheck your bisection, since that was later reverted.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre

2010-11-10 22:38:07

by Johannes Hirte

[permalink] [raw]
Subject: Re: [bisected] i915 regression in post 2.6.36 kernels

On Wednesday 10 November 2010 08:46:40 Chris Wilson wrote:
> On Wed, 10 Nov 2010 08:02:19 +0100, Johannes Hirte <[email protected]> wrote:
> > With the latest kernel, I don't get any windows in KDE displayed. After
> > starting kdm, I get the background picture and the mouse cursor but not the
> > login window. I can login blindly and a ps on console shows me that the
> > expected KDE processes are started but still nothing is displayed.
> > I've bisected this to:
> >
> > 5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad commit
> > commit 5c12a07e8073295ce8b57a822f811ac34e4f8420
> > Author: Chris Wilson <[email protected]>
> > Date: Wed Sep 22 11:22:30 2010 +0100
> >
> > drm/i915: Drop ring->lazy_request
> >
> > We are not currently using it as intended, so remove the complication.
> >
> > Signed-off-by: Chris Wilson <[email protected]>
>
> May I ask you to recheck your bisection, since that was later reverted.
> -Chris

Did so. I've started with v2.6.36 for bisect good and
f6614b7bb405a9b35dd28baea989a749492c46b2 for bisect bad (was HEAD) in this
case. Again I ended in 5c12a07e8073295ce8b57a822f811ac34e4f8420 as the first
bad commit. The regression was introduced there, as the commit before is fine.
If it was reverted, the regression should be fixed by this. But I don't find
neither the fix/revert nor the reintroduction of the regression.

regrards,
Johannes

2010-11-12 18:21:18

by Florian Mickler

[permalink] [raw]
Subject: Re: [bisected] i915 regression in post 2.6.36 kernels

On Wed, 10 Nov 2010 23:39:35 +0100
Johannes Hirte <[email protected]> wrote:

> On Wednesday 10 November 2010 08:46:40 Chris Wilson wrote:
> > On Wed, 10 Nov 2010 08:02:19 +0100, Johannes Hirte <[email protected]> wrote:
> > > With the latest kernel, I don't get any windows in KDE displayed. After
> > > starting kdm, I get the background picture and the mouse cursor but not the
> > > login window. I can login blindly and a ps on console shows me that the
> > > expected KDE processes are started but still nothing is displayed.
> > > I've bisected this to:
> > >
> > > 5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad commit
> > > commit 5c12a07e8073295ce8b57a822f811ac34e4f8420
> > > Author: Chris Wilson <[email protected]>
> > > Date: Wed Sep 22 11:22:30 2010 +0100
> > >
> > > drm/i915: Drop ring->lazy_request
> > >
> > > We are not currently using it as intended, so remove the complication.
> > >
> > > Signed-off-by: Chris Wilson <[email protected]>
> >
> > May I ask you to recheck your bisection, since that was later reverted.
> > -Chris
>
> Did so. I've started with v2.6.36 for bisect good and
> f6614b7bb405a9b35dd28baea989a749492c46b2 for bisect bad (was HEAD) in this
> case. Again I ended in 5c12a07e8073295ce8b57a822f811ac34e4f8420 as the first
> bad commit. The regression was introduced there, as the commit before is fine.
> If it was reverted, the regression should be fixed by this. But I don't find
> neither the fix/revert nor the reintroduction of the regression.
>
> regrards,
> Johannes

The revert is a56ba56c275b1c2b982c8901ab92bf5a0fd0b757 .

Regards,
Flo

2010-11-12 20:07:04

by Johannes Hirte

[permalink] [raw]
Subject: Re: [bisected] i915 regression in post 2.6.36 kernels

On Friday 12 November 2010 19:20:46 Florian Mickler wrote:
> On Wed, 10 Nov 2010 23:39:35 +0100
> Johannes Hirte <[email protected]> wrote:
>
> > On Wednesday 10 November 2010 08:46:40 Chris Wilson wrote:
> > > On Wed, 10 Nov 2010 08:02:19 +0100, Johannes Hirte <[email protected]> wrote:
> > > > With the latest kernel, I don't get any windows in KDE displayed. After
> > > > starting kdm, I get the background picture and the mouse cursor but not the
> > > > login window. I can login blindly and a ps on console shows me that the
> > > > expected KDE processes are started but still nothing is displayed.
> > > > I've bisected this to:
> > > >
> > > > 5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad commit
> > > > commit 5c12a07e8073295ce8b57a822f811ac34e4f8420
> > > > Author: Chris Wilson <[email protected]>
> > > > Date: Wed Sep 22 11:22:30 2010 +0100
> > > >
> > > > drm/i915: Drop ring->lazy_request
> > > >
> > > > We are not currently using it as intended, so remove the complication.
> > > >
> > > > Signed-off-by: Chris Wilson <[email protected]>
> > >
> > > May I ask you to recheck your bisection, since that was later reverted.
> > > -Chris
> >
> > Did so. I've started with v2.6.36 for bisect good and
> > f6614b7bb405a9b35dd28baea989a749492c46b2 for bisect bad (was HEAD) in this
> > case. Again I ended in 5c12a07e8073295ce8b57a822f811ac34e4f8420 as the first
> > bad commit. The regression was introduced there, as the commit before is fine.
> > If it was reverted, the regression should be fixed by this. But I don't find
> > neither the fix/revert nor the reintroduction of the regression.
> >
> > regrards,
> > Johannes
>
> The revert is a56ba56c275b1c2b982c8901ab92bf5a0fd0b757 .

Thanks for the hint. This was the commit I was searching for. Unfortunately
this version shows the same regression. I've checked again, that
5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad version.
2.6.36-rc5-00228-g2896b53 (2896b5397570f6857fd5d0e0533f640b05b1d162) works
2.6.36-rc5-00229-g5c12a07 (5c12a07e8073295ce8b57a822f811ac34e4f8420) doesn't.
Someone with knowledge of the code should have a look what's different
between 5c12a07e8073295ce8b57a822f811ac34e4f8420 and its revert.

regards,
Johannes

2010-11-13 22:32:51

by Johannes Hirte

[permalink] [raw]
Subject: Re: [bisected] i915 regression in post 2.6.36 kernels

On Friday 12 November 2010 21:08:34 Johannes Hirte wrote:
> On Friday 12 November 2010 19:20:46 Florian Mickler wrote:
> > On Wed, 10 Nov 2010 23:39:35 +0100
> > Johannes Hirte <[email protected]> wrote:
> >
> > > On Wednesday 10 November 2010 08:46:40 Chris Wilson wrote:
> > > > On Wed, 10 Nov 2010 08:02:19 +0100, Johannes Hirte <[email protected]> wrote:
> > > > > With the latest kernel, I don't get any windows in KDE displayed. After
> > > > > starting kdm, I get the background picture and the mouse cursor but not the
> > > > > login window. I can login blindly and a ps on console shows me that the
> > > > > expected KDE processes are started but still nothing is displayed.
> > > > > I've bisected this to:
> > > > >
> > > > > 5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad commit
> > > > > commit 5c12a07e8073295ce8b57a822f811ac34e4f8420
> > > > > Author: Chris Wilson <[email protected]>
> > > > > Date: Wed Sep 22 11:22:30 2010 +0100
> > > > >
> > > > > drm/i915: Drop ring->lazy_request
> > > > >
> > > > > We are not currently using it as intended, so remove the complication.
> > > > >
> > > > > Signed-off-by: Chris Wilson <[email protected]>
> > > >
> > > > May I ask you to recheck your bisection, since that was later reverted.
> > > > -Chris
> > >
> > > Did so. I've started with v2.6.36 for bisect good and
> > > f6614b7bb405a9b35dd28baea989a749492c46b2 for bisect bad (was HEAD) in this
> > > case. Again I ended in 5c12a07e8073295ce8b57a822f811ac34e4f8420 as the first
> > > bad commit. The regression was introduced there, as the commit before is fine.
> > > If it was reverted, the regression should be fixed by this. But I don't find
> > > neither the fix/revert nor the reintroduction of the regression.
> > >
> > > regrards,
> > > Johannes
> >
> > The revert is a56ba56c275b1c2b982c8901ab92bf5a0fd0b757 .
>
> Thanks for the hint. This was the commit I was searching for. Unfortunately
> this version shows the same regression. I've checked again, that
> 5c12a07e8073295ce8b57a822f811ac34e4f8420 is the first bad version.
> 2.6.36-rc5-00228-g2896b53 (2896b5397570f6857fd5d0e0533f640b05b1d162) works
> 2.6.36-rc5-00229-g5c12a07 (5c12a07e8073295ce8b57a822f811ac34e4f8420) doesn't.
> Someone with knowledge of the code should have a look what's different
> between 5c12a07e8073295ce8b57a822f811ac34e4f8420 and its revert.
>
> regards,
> Johannes

I've found it. 5c12a07e8073295ce8b57a822f811ac34e4f8420 contains

static void
@@ -1945,11 +1933,6 @@ i915_gem_flush_ring(struct drm_device *dev,
{
ring->flush(dev, ring, invalidate_domains, flush_domains);
i915_gem_process_flushing_list(dev, flush_domains, ring);
-
- if (ring->outstanding_lazy_request) {
- (void)i915_add_request(dev, file_priv, NULL, ring);
- ring->outstanding_lazy_request = false;
- }
}

which wasn't redone by a56ba56c275b1c2b982c8901ab92bf5a0fd0b757. After adding
those five lines it works for me.

regards,
Johannes