| From da331ba8e9c5de72a27e50f71105395bba6eebe0 Mon Sep 17 00:00:00 2001 |
| From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> |
| Date: Wed, 3 Jul 2013 15:00:43 -0700 |
| Subject: drivers/dma/pl330.c: fix locking in pl330_free_chan_resources() |
| |
| From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> |
| |
| commit da331ba8e9c5de72a27e50f71105395bba6eebe0 upstream. |
| |
| tasklet_kill() may sleep so call it before taking pch->lock. |
| |
| Fixes following lockup: |
| |
| BUG: scheduling while atomic: cat/2383/0x00000002 |
| Modules linked in: |
| unwind_backtrace+0x0/0xfc |
| __schedule_bug+0x4c/0x58 |
| __schedule+0x690/0x6e0 |
| sys_sched_yield+0x70/0x78 |
| tasklet_kill+0x34/0x8c |
| pl330_free_chan_resources+0x24/0x88 |
| dma_chan_put+0x4c/0x50 |
| [...] |
| BUG: spinlock lockup suspected on CPU#0, swapper/0/0 |
| lock: 0xe52aa04c, .magic: dead4ead, .owner: cat/2383, .owner_cpu: 1 |
| unwind_backtrace+0x0/0xfc |
| do_raw_spin_lock+0x194/0x204 |
| _raw_spin_lock_irqsave+0x20/0x28 |
| pl330_tasklet+0x2c/0x5a8 |
| tasklet_action+0xfc/0x114 |
| __do_softirq+0xe4/0x19c |
| irq_exit+0x98/0x9c |
| handle_IPI+0x124/0x16c |
| gic_handle_irq+0x64/0x68 |
| __irq_svc+0x40/0x70 |
| cpuidle_wrap_enter+0x4c/0xa0 |
| cpuidle_enter_state+0x18/0x68 |
| cpuidle_idle_call+0xac/0xe0 |
| cpu_idle+0xac/0xf0 |
| |
| Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> |
| Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> |
| Acked-by: Jassi Brar <jassisinghbrar@gmail.com> |
| Cc: Vinod Koul <vinod.koul@linux.intel.com> |
| Cc: Tomasz Figa <t.figa@samsung.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/dma/pl330.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/dma/pl330.c |
| +++ b/drivers/dma/pl330.c |
| @@ -2485,10 +2485,10 @@ static void pl330_free_chan_resources(st |
| struct dma_pl330_chan *pch = to_pchan(chan); |
| unsigned long flags; |
| |
| - spin_lock_irqsave(&pch->lock, flags); |
| - |
| tasklet_kill(&pch->task); |
| |
| + spin_lock_irqsave(&pch->lock, flags); |
| + |
| pl330_release_channel(pch->pl330_chid); |
| pch->pl330_chid = NULL; |
| |
