| Message ID | 20180702150206.29244-1-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On 02-07-18, 17:02, Geert Uytterhoeven wrote: > During system reboot or halt, with lockdep enabled: > > ================================ > WARNING: inconsistent lock state > 4.18.0-rc1-salvator-x-00002-g9203dbec90a68103 #41 Tainted: G W > -------------------------------- > inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. > reboot/2779 [HC0[0]:SC0[0]:HE1:SE1] takes: > 0000000098ae4ad3 (&(&rchan->lock)->rlock){?.-.}, at: rcar_dmac_shutdown+0x58/0x6c > {IN-HARDIRQ-W} state was registered at: > lock_acquire+0x208/0x238 > _raw_spin_lock+0x40/0x54 > rcar_dmac_isr_channel+0x28/0x200 > __handle_irq_event_percpu+0x1c0/0x3c8 > handle_irq_event_percpu+0x34/0x88 > handle_irq_event+0x48/0x78 > handle_fasteoi_irq+0xc4/0x12c > generic_handle_irq+0x18/0x2c > __handle_domain_irq+0xa8/0xac > gic_handle_irq+0x78/0xbc > el1_irq+0xec/0x1c0 > arch_cpu_idle+0xe8/0x1bc > default_idle_call+0x2c/0x30 > do_idle+0x144/0x234 > cpu_startup_entry+0x20/0x24 > rest_init+0x27c/0x290 > start_kernel+0x430/0x45c > irq event stamp: 12177 > hardirqs last enabled at (12177): [<ffffff800881d804>] _raw_spin_unlock_irq+0x2c/0x4c > hardirqs last disabled at (12176): [<ffffff800881d638>] _raw_spin_lock_irq+0x1c/0x60 > softirqs last enabled at (11948): [<ffffff8008081da8>] __do_softirq+0x160/0x4ec > softirqs last disabled at (11935): [<ffffff80080ec948>] irq_exit+0xa0/0xfc > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(&(&rchan->lock)->rlock); > <Interrupt> > lock(&(&rchan->lock)->rlock); > > *** DEADLOCK *** > > 3 locks held by reboot/2779: > #0: 00000000bfabfa74 (reboot_mutex){+.+.}, at: sys_reboot+0xdc/0x208 > #1: 00000000c75d8c3a (&dev->mutex){....}, at: device_shutdown+0xc8/0x1c4 > #2: 00000000ebec58ec (&dev->mutex){....}, at: device_shutdown+0xd8/0x1c4 > > stack backtrace: > CPU: 6 PID: 2779 Comm: reboot Tainted: G W 4.18.0-rc1-salvator-x-00002-g9203dbec90a68103 #41 > Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT) > Call trace: > dump_backtrace+0x0/0x148 > show_stack+0x14/0x1c > dump_stack+0xb0/0xf0 > print_usage_bug.part.26+0x1c4/0x27c > mark_lock+0x38c/0x610 > __lock_acquire+0x3fc/0x14d4 > lock_acquire+0x208/0x238 > _raw_spin_lock+0x40/0x54 > rcar_dmac_shutdown+0x58/0x6c > platform_drv_shutdown+0x20/0x2c > device_shutdown+0x160/0x1c4 > kernel_restart_prepare+0x34/0x3c > kernel_restart+0x14/0x5c > sys_reboot+0x160/0x208 > el0_svc_naked+0x30/0x34 > > rcar_dmac_stop_all_chan() takes the channel lock while stopping a > channel, but does not disable interrupts, leading to a deadlock when a > DMAC interrupt comes in. Before, the same code block was called from an > interrupt handler, hence taking the spinlock was sufficient. > > Fix this by disabling local interrupts while taking the spinlock. Applied, thanks
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 279c930c4a7635e0..4e4d183190bd0c9c 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -823,9 +823,9 @@ static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac) struct rcar_dmac_chan *chan = &dmac->channels[i]; /* Stop and reinitialize the channel. */ - spin_lock(&chan->lock); + spin_lock_irq(&chan->lock); rcar_dmac_chan_halt(chan); - spin_unlock(&chan->lock); + spin_unlock_irq(&chan->lock); } }
During system reboot or halt, with lockdep enabled: ================================ WARNING: inconsistent lock state 4.18.0-rc1-salvator-x-00002-g9203dbec90a68103 #41 Tainted: G W -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. reboot/2779 [HC0[0]:SC0[0]:HE1:SE1] takes: 0000000098ae4ad3 (&(&rchan->lock)->rlock){?.-.}, at: rcar_dmac_shutdown+0x58/0x6c {IN-HARDIRQ-W} state was registered at: lock_acquire+0x208/0x238 _raw_spin_lock+0x40/0x54 rcar_dmac_isr_channel+0x28/0x200 __handle_irq_event_percpu+0x1c0/0x3c8 handle_irq_event_percpu+0x34/0x88 handle_irq_event+0x48/0x78 handle_fasteoi_irq+0xc4/0x12c generic_handle_irq+0x18/0x2c __handle_domain_irq+0xa8/0xac gic_handle_irq+0x78/0xbc el1_irq+0xec/0x1c0 arch_cpu_idle+0xe8/0x1bc default_idle_call+0x2c/0x30 do_idle+0x144/0x234 cpu_startup_entry+0x20/0x24 rest_init+0x27c/0x290 start_kernel+0x430/0x45c irq event stamp: 12177 hardirqs last enabled at (12177): [<ffffff800881d804>] _raw_spin_unlock_irq+0x2c/0x4c hardirqs last disabled at (12176): [<ffffff800881d638>] _raw_spin_lock_irq+0x1c/0x60 softirqs last enabled at (11948): [<ffffff8008081da8>] __do_softirq+0x160/0x4ec softirqs last disabled at (11935): [<ffffff80080ec948>] irq_exit+0xa0/0xfc other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&rchan->lock)->rlock); <Interrupt> lock(&(&rchan->lock)->rlock); *** DEADLOCK *** 3 locks held by reboot/2779: #0: 00000000bfabfa74 (reboot_mutex){+.+.}, at: sys_reboot+0xdc/0x208 #1: 00000000c75d8c3a (&dev->mutex){....}, at: device_shutdown+0xc8/0x1c4 #2: 00000000ebec58ec (&dev->mutex){....}, at: device_shutdown+0xd8/0x1c4 stack backtrace: CPU: 6 PID: 2779 Comm: reboot Tainted: G W 4.18.0-rc1-salvator-x-00002-g9203dbec90a68103 #41 Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT) Call trace: dump_backtrace+0x0/0x148 show_stack+0x14/0x1c dump_stack+0xb0/0xf0 print_usage_bug.part.26+0x1c4/0x27c mark_lock+0x38c/0x610 __lock_acquire+0x3fc/0x14d4 lock_acquire+0x208/0x238 _raw_spin_lock+0x40/0x54 rcar_dmac_shutdown+0x58/0x6c platform_drv_shutdown+0x20/0x2c device_shutdown+0x160/0x1c4 kernel_restart_prepare+0x34/0x3c kernel_restart+0x14/0x5c sys_reboot+0x160/0x208 el0_svc_naked+0x30/0x34 rcar_dmac_stop_all_chan() takes the channel lock while stopping a channel, but does not disable interrupts, leading to a deadlock when a DMAC interrupt comes in. Before, the same code block was called from an interrupt handler, hence taking the spinlock was sufficient. Fix this by disabling local interrupts while taking the spinlock. Fixes: 9203dbec90a68103 ("dmaengine: rcar-dmac: don't use DMAC error interrupt") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- drivers/dma/sh/rcar-dmac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)