Re: [BUG 3.7-rc1] nouveau cli->mutex possible recursive lockingdetected

[Arend van Spriel]

On 10/24/2012 02:45 PM, Arend van Spriel wrote:
> On 10/24/2012 01:14 PM, Arend van Spriel wrote:
> > On 10/16/2012 02:43 PM, Stanislaw Gruszka wrote:
> > > I have this lockdep warning on wireless-testing tree based
> > > on 3.7-rc1 (no other patches except wireless bits).
> > >
> > > =============================================
> > > Restarting tasks ... done.
> > > [ INFO: possible recursive locking detected ]
> > > 3.7.0-rc1-wl+ #2 Not tainted
> > > ---------------------------------------------
> > > Xorg/2269 is trying to acquire lock:
> > >   (&cli->mutex){+.+.+.}, at: [<ffffffffa012a27f>]
> > > nouveau_bo_move_m2mf+0x5f/0x170 [nouveau]
> > >
> > > but task is already holding lock:
> > >   (&cli->mutex){+.+.+.}, at: [<ffffffffa012f3c4>]
> > > nouveau_abi16_get+0x34/0x100 [nouveau]
> >
> > I have observed the same bug so I built and tested v3.7-rc2 tag with
> > lockdep enabled. It has the same problem and it results in a failure to
> > resume after suspend. See below.
> >
> > Gr. AvS
>
> digging into the trace:
>
>
> nouveau_gem_ioctl_pushbuf() calls nouveau_abi16_get() which grabs the
> mutex. Assume this should protect the chan variable passed to
> nouveau_gem_pushbuf_validate(), which does a bit more that validate as
> it ends up in nouveau_bo_move_m2mf() which uses the drm->chan. However,
> it deadlocks before that.
>
> Gr. AvS

Maybe this helps. The two locations where the lock is grabbed are from 
the same commit (see below).

Gr. AvS

commit ebb945a94bba2ce8dff7b0942ff2b3f2a52a0a69
Author: Ben Skeggs <bskeggs@xxxxxxxxxx>
Date:   Fri Jul 20 08:17:34 2012 +1000

    drm/nouveau: port all engines to new engine module format

    This is a HUGE commit, but it's not nearly as bad as it looks - any 
problems
    can be isolated to a particular chipset and engine combination.  It was
    simply too difficult to port each one at a time, the compat layers are
    *already* ridiculous.

    Most of the changes here are simply to the glue, the process for 
each of the
    engine modules was to start with a standard skeleton and copy+paste 
the old
    code into the appropriate places, fixing up variable names etc as 
needed.

    v2: Marcin Slusarz <marcin.slusarz@xxxxxxxxx>
    - fix find/replace bug in license header

    v3: Ben Skeggs <bskeggs@xxxxxxxxxx>
    - bump indirect pushbuf size to 8KiB, 4KiB barely enough for 
userspace and
      left no space for kernel's requirements during GEM pushbuf 
submission.
    - fix duplicate assignments noticed by clang

    v4: Marcin Slusarz <marcin.slusarz@xxxxxxxxx>
    - add sparse annotations to nv04_fifo_pause/nv04_fifo_start
    - use ioread32_native/iowrite32_native for fifo control registers

    v5: Ben Skeggs <bskeggs@xxxxxxxxxx>
    - rebase on v3.6-rc4, modified to keep copy engine fix intact
    - nv10/fence: unmap fence bo before destroying
    - fixed fermi regression when using nvidia gr fuc
    - fixed typo in supported dma_mask checking

    Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/