From: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Subject: drivers/dma/pl330.c: fix locking in pl330_free_chan_resources() tasklet_kill() may sleep so call it before taking pch->lock. Fixes following lockup: [ 345.470000] BUG: scheduling while atomic: cat/2383/0x00000002 [ 345.470000] Modules linked in: [ 345.470000] [<c0015858>] (unwind_backtrace+0x0/0xfc) from [<c004d980>] (__schedule_bug+0x4c/0x58) [ 345.470000] [<c004d980>] (__schedule_bug+0x4c/0x58) from [<c0360b6c>] (__schedule+0x690/0x6e0) [ 345.470000] [<c0360b6c>] (__schedule+0x690/0x6e0) from [<c004f2b4>] (sys_sched_yield+0x70/0x78) [ 345.470000] [<c004f2b4>] (sys_sched_yield+0x70/0x78) from [<c002acec>] (tasklet_kill+0x34/0x8c) [ 345.470000] [<c002acec>] (tasklet_kill+0x34/0x8c) from [<c01da4cc>] (pl330_free_chan_resources+0x24/0x88) [ 345.470000] [<c01da4cc>] (pl330_free_chan_resources+0x24/0x88) from [<c01d81f4>] (dma_chan_put+0x4c/0x50) [ 345.470000] [<c01d81f4>] (dma_chan_put+0x4c/0x50) from [<c01d82c0>] (dma_release_channel+0x28/0x98) [...] [ 368.335000] BUG: spinlock lockup suspected on CPU#0, swapper/0/0 [ 368.340000] lock: 0xe52aa04c, .magic: dead4ead, .owner: cat/2383, .owner_cpu: 1 [ 368.350000] [<c0015858>] (unwind_backtrace+0x0/0xfc) from [<c01b3d78>] (do_raw_spin_lock+0x194/0x204) [ 368.360000] [<c01b3d78>] (do_raw_spin_lock+0x194/0x204) from [<c0361adc>] (_raw_spin_lock_irqsave+0x20/0x28) [ 368.365000] [<c0361adc>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c01da80c>] (pl330_tasklet+0x2c/0x5a8) [ 368.375000] [<c01da80c>] (pl330_tasklet+0x2c/0x5a8) from [<c002ac04>] (tasklet_action+0xfc/0x114) [ 368.385000] [<c002ac04>] (tasklet_action+0xfc/0x114) from [<c002b204>] (__do_softirq+0xe4/0x19c) [ 368.395000] [<c002b204>] (__do_softirq+0xe4/0x19c) from [<c002b398>] (irq_exit+0x98/0x9c) [ 368.405000] [<c002b398>] (irq_exit+0x98/0x9c) from [<c0013ebc>] (handle_IPI+0x124/0x16c) [ 368.410000] [<c0013ebc>] (handle_IPI+0x124/0x16c) from [<c000857c>] (gic_handle_irq+0x64/0x68) [ 368.420000] [<c000857c>] (gic_handle_irq+0x64/0x68) from [<c000e740>] (__irq_svc+0x40/0x70) [ 368.430000] Exception stack(0xc04a3f00 to 0xc04a3f48) [ 368.435000] 3f00: c04a3f48 00000000 6f9e23e8 00000050 c07492c8 c04a3f48 00000000 c04ccc88 [ 368.440000] 3f20: 6f9dbac3 00000050 6f9e23e8 00000050 3b9aca00 c04a3f48 c005cfa4 c02946d4 [ 368.450000] 3f40: 60000013 ffffffff [ 368.455000] [<c000e740>] (__irq_svc+0x40/0x70) from [<c02946d4>] (cpuidle_wrap_enter+0x4c/0xa0) [ 368.460000] [<c02946d4>] (cpuidle_wrap_enter+0x4c/0xa0) from [<c02940dc>] (cpuidle_enter_state+0x18/0x68) [ 368.470000] [<c02940dc>] (cpuidle_enter_state+0x18/0x68) from [<c02948e0>] (cpuidle_idle_call+0xac/0xe0) [ 368.480000] [<c02948e0>] (cpuidle_idle_call+0xac/0xe0) from [<c00102f8>] (cpu_idle+0xac/0xf0) [ 368.490000] [<c00102f8>] (cpu_idle+0xac/0xf0) from [<c04796a0>] (start_kernel+0x28c/0x294) Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> Acked-by: Jassi Brar <jassisinghbrar@xxxxxxxxx> Cc: Vinod Koul <vinod.koul@xxxxxxxxxxxxxxx> Cc: Tomasz Figa <t.figa@xxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/dma/pl330.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN drivers/dma/pl330.c~drivers-dma-pl330c-fix-locking-in-pl330_free_chan_resources drivers/dma/pl330.c --- a/drivers/dma/pl330.c~drivers-dma-pl330c-fix-locking-in-pl330_free_chan_resources +++ a/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; _ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html