[Bug 29140] New: [rs690] Freeze at Xorg startup when using KMS

[Bug 29140] New: [rs690] Freeze at Xorg startup when using KMS

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=29140

           Summary: [rs690] Freeze at Xorg startup when using KMS
           Product: DRI
           Version: XOrg CVS
          Platform: x86-64 (AMD64)
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: DRM/Radeon
        AssignedTo: dri-devel@lists.freedesktop.org
        ReportedBy: steckdenis@yahoo.fr


Created an attachment (id=37174)
 --> (https://bugs.freedesktop.org/attachment.cgi?id=37174)
Complete dmesg (radeon module loaded just after the last line speaking about a
segfault of glxinfo)

Hello,

I have an ATI Radeon X1270 card (rs690m), with 128 Mio of sideport memory and
256 Mio of shared RAM. This memory configuration caused the bug #27529 .

I use the 2.6.35-rc5 kernel (linus-tree), Mesa git (as of the 17th of July
2010, commit 184abe8e26f76a50ede43d503aa6bf129d8d6b76, "llvmpipe: Remove unused
variable in lp_test_sincos."), libdrm git (as of the first of July 2010, commit
b803918f3f77c62edf22e78cb2095be399753423, "drm mode: Return -errno on
drmIoctl() failure") and xf86-video-ati git (as of the 15th of July, commit
cdeb1949c820242f05a8897d3ddd0718f204dacf, "kms: don't call cursor helper if
using software cursor").

Because of the bug #27529, I used to boot my netbook with the
"radeon.modeset=0" param, to avoir screen corruptions.

Then, I went to vacations. When I returned back to home, I wanted to try the
latest versions of all my favorite softwares, especially the shiny new kernel,
containing the fix of #27529.

I updated all my software stack to the versions I mentionned in the second
paragraph, changed "radeon.modeset=0" to "radeon.modeset=1" and rebooted.

The reboot was ok. All my services started up nicely, except KDM. When the X
server attempts to start, the screen goes black, with a small text cursor at
its top left corner. This cursor doesn't move or blinks. The computer doesn't
go farther in the boot sequence, it freezes.

I rebooted, using the nomodeset option, and killed KDM (which started fine). I
launched a small shell loop that continuously write the dmesg output in a file
and launched it.

While it was running, I unloaded the radeon module and reloaded it with the
"modeset=1" parameter. All went fine, my screen was ok, with my text console on
it. Then, I restarted KDM, which attempted to start Xorg.

The same bug came again. During the "freeze", I was able to see the activity of
my hard disk drive (the dmesg loop contains a sync). It makes me thinking that
the computer is not hard frozen, only the graphical part. I cannot go to any
virtual console at this point, and I rebooted.

I attached my complete dmesg, as captured by my small script.

Thanks for resolving this bug, I hope it is the last one I will see before
having a nice KMS-enabled netbook, and being able to give a try to Gallium3D,
which is needed to a have the very nice Blur effect of KWin on my hardware.

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

Alex Deucher <agd5f@yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #37174|text/x-log                  |text/plain
          mime type|                            |
  Attachment #37174|0                           |1
           is patch|                            |

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=29140

steckdenis@yahoo.fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Product|DRI                         |xorg
            Version|XOrg CVS                    |git
          Component|DRM/Radeon                  |Driver/Radeon
         AssignedTo|dri-devel@lists.freedesktop |xorg-driver-ati@lists.x.org
                   |.org                        |
          QAContact|                            |xorg-team@lists.x.org

--- Comment #1 from steckdenis@yahoo.fr 2010-07-23 02:05:34 PDT ---
Hello,

I tested the new 2.6.35-rc6 kernel, and the bug also happens with this one. I
use Mesa Git as of this morning, and the same xf86-video-ati and libdrm
versions as in my last post.

I also tested with the "Option "NoAccel" "true"" in my xorg.conf, and the bug
didn't happened. src/radeon_kms.c in the xf86-video-ati driver loads the EXA
Xorg module when NoAccel is "false", so I didn't load it with NoAccel was
"true". The bug may be there.

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

steckdenis@yahoo.fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Product|xorg                        |DRI
            Version|git                         |DRI CVS
          Component|Driver/Radeon               |DRM/Radeon
         AssignedTo|xorg-driver-ati@lists.x.org |dri-devel@lists.freedesktop
                   |                            |.org
          QAContact|xorg-team@lists.x.org       |

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=29140

steckdenis@yahoo.fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[rs690] Freeze at Xorg      |[rs690] Freeze at Xorg
                   |startup when using KMS      |startup when using KMS and
                   |                            |multiple screens

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

--- Comment #8 from steckdenis@yahoo.fr 2010-08-09 06:00:25 PDT ---
Created an attachment (id=37722)
 --> (https://bugs.freedesktop.org/attachment.cgi?id=37722)
Strace output when running Xorg

Hello,

I tried today to reproduce this bug using Xorg Git, Linux 2.6.35 and Mesa Git.
The bug happened again, except that I have some very interesting informations
for you.

GDB wasn't helpfull because the bug is in the radeon kernel module. I
discovered that Linux prints to dmesg a complete kernel stacktrace when an
application is locked up by a mutex. By chance, it is just what is happening
with Xorg, so I have a stack trace :

INFO: task Xorg:2948 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Xorg          D 00000000ffffc694     0  2948      1 0x00400005
 ffff8800683e7788 0000000000000082 ffff880001814f00 ffff8800683a1180
 0000000000014f00 0000000000014f00 ffff8800683e7fd8 ffff8800683e7fd8
 ffff8800683e7fd8 ffff88006c1df780 ffff8800683e7fd8 0000000000014f00
Call Trace:
 [<ffffffff81356bef>] __mutex_lock_slowpath+0x13f/0x310
 [<ffffffff81356dd1>] mutex_lock+0x11/0x30
 [<ffffffffa04feba5>] radeon_ring_lock+0x25/0x50 [radeon]
 [<ffffffffa0511f01>] r300_gpu_is_lockup+0x71/0x190 [radeon]
 [<ffffffffa04e753e>] radeon_fence_wait+0x33e/0x3d0 [radeon]
 [<ffffffff8106f610>] ? autoremove_wake_function+0x0/0x40
 [<ffffffffa04e6f85>] ? radeon_fence_emit+0xe5/0x130 [radeon]
 [<ffffffffa0545a58>] radeon_pm_set_clocks+0x3c8/0x5f0 [radeon]
 [<ffffffff81356ce3>] ? __mutex_lock_slowpath+0x233/0x310
 [<ffffffffa0546908>] radeon_pm_compute_clocks+0xd8/0x270 [radeon]
 [<ffffffffa04dadf3>] atombios_crtc_mode_fixup+0x23/0x40 [radeon]
 [<ffffffffa044a06b>] drm_crtc_helper_set_mode+0x15b/0x3f0 [drm_kms_helper]
 [<ffffffffa0506a7a>] ? r100_cs_packet_next_reloc+0x4a/0x1e0 [radeon]
 [<ffffffffa044abe7>] drm_crtc_helper_set_config+0x797/0x820 [drm_kms_helper]
 [<ffffffffa03e6ccf>] ? drm_mode_object_find+0x5f/0x80 [drm]
 [<ffffffffa03e7f9f>] drm_mode_setcrtc+0x2cf/0x3a0 [drm]
 [<ffffffffa03da99c>] drm_ioctl+0x37c/0x460 [drm]
 [<ffffffffa03e7cd0>] ? drm_mode_setcrtc+0x0/0x3a0 [drm]
 [<ffffffff8112d04c>] vfs_ioctl+0x3c/0xd0
 [<ffffffff8112d62c>] do_vfs_ioctl+0x7c/0x500
 [<ffffffff8112db29>] sys_ioctl+0x79/0x90
 [<ffffffff8100a017>] tracesys+0xd9/0xde

To be even more complete, I launched Xorg with strace, to see when all things
are happening. I attached the strace output to this bug.

The last line, that is not complete, is when Xorg tries to call the
DRM_IOCTL_MODE_SETCRTC. The two previous ioctls are DRM_IOCTL_MODE_ADDFB
followed by DRM_IOCTL_MODE_SETGAMMA.

This bug doesn't happen when I use only one monitor (the internal LVDS), but
only when I also use my external VGA monitor (without it, I think
DRM_IOCTL_MODE_SETCRTC is never called).

I use an ATI Radeon X1270 (rs690m with 128Mio sideport memory) on a Packard
Bell Dot/MA.FR netbook (it's the same as the Gateway Gateway LT3103u, but with
a Packard Bell logo on it :) ).

I hope these informations will help you.

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

--- Comment #9 from steckdenis@yahoo.fr 2010-08-12 09:57:45 PDT ---
Hello,

I think I found the problem, but I am unfortunately unable to fix it (I don't
know the radeon module enough).

A change between the 2.6.34 and 2.6.35 kernels added a bunch of functions in
drivers/gpu/drm/radeon/radeon_pm.c. The function that causes troubles to me is
radeon_pm_set_clocks(struct radeon_device *rdev); .

This function begins by locking three mutexes, including rdev->cp.mutex.

My card is a r300, so the code goes through the "else" branch of the if. This
branch contains a call to radeon_fence_emit.

Now in radeon_fence.c . I don't know how, but this function happens to call
radeon_fence_wait. The problem is that radeon_fence_wait calls
r300_gpu_is_lockup, by branching in "if
(unlikely(!radeon_fence_signaled(fence))) {".

In r300.c : r300_gpu_is_lockup, called by radeon_fence_wait, calls
radeon_ring_lock, because it wants to write in the ring.

In radeon_ring.c : radeon_ring_lock begins by calling
"mutex_lock(&rdev->cp.mutex);", the exact same mutex as the one already locked
by radeon_pm_set_clocks. That seems to be the problem.

Cheers.

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

--- Comment #10 from Alex Deucher <agd5f@yahoo.com> 2010-08-12 16:17:12 PDT ---
Created an attachment (id=37828)
 View: https://bugs.freedesktop.org/attachment.cgi?id=37828
 Review: https://bugs.freedesktop.org/review?bug=29140&attachment=37828

possible fix

Does this patch help?

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

--- Comment #11 from steckdenis@yahoo.fr 2010-08-13 00:55:19 PDT ---
I applied the patch on a vanilla 2.6.35.1 kernel, and it works ! 

Thanks.

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

--- Comment #12 from Alex Deucher <agd5f@yahoo.com> 2010-08-13 07:54:14 PDT ---
I've sent the patch to Dave.  Thanks for tracking this down.

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[Bug 29140] [rs690] Freeze at Xorg startup when using KMS and multiple screens

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https://bugs.freedesktop.org/show_bug.cgi?id=29140

Jerome Glisse <glisse@freedesktop.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

--- Comment #13 from Jerome Glisse <glisse@freedesktop.org> 2010-08-16 10:15:28 PDT ---
Closing

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