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authorBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>2013-07-03 15:00:43 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-21 18:21:35 -0700
commitc14a4eaf8a43a295176942c7a43a999b4557f7c3 (patch)
treec3b9a1e103edfef1d5babbcf78597d8deaee1364
parent9131e72c764bd7ea9554392edab26a368a765c4d (diff)
downloadvexpress-lsk-c14a4eaf8a43a295176942c7a43a999b4557f7c3.tar.gz
drivers/dma/pl330.c: fix locking in pl330_free_chan_resources()
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>
-rw-r--r--drivers/dma/pl330.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index a17553f7c02..7ec82f0667e 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2485,10 +2485,10 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
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;