linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR
@ 2018-09-11 14:31 jun qian
  2018-09-11 15:17 ` Lucas Stach
  0 siblings, 1 reply; 2+ messages in thread
From: jun qian @ 2018-09-11 14:31 UTC (permalink / raw)
  To: Dan Williams, Vinod Koul, Jun Nie, Baoyou Xie, Shawn Guo
  Cc: linux-arm-kernel, dmaengine, linux-kernel, jun qian, Barry song

As you are already in ISR, it is unnecessary to call spin_lock_irqsave.

Signed-off-by: jun qian <hangdianqj@163.com>
Cc: Barry song <21cnbao@gmail.com>
---
 drivers/dma/zx_dma.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/zx_dma.c b/drivers/dma/zx_dma.c
index 2571bc7693df..111ab2db83b1 100644
--- a/drivers/dma/zx_dma.c
+++ b/drivers/dma/zx_dma.c
@@ -288,9 +288,8 @@ static irqreturn_t zx_dma_int_handler(int irq, void *dev_id)
 		p = &d->phy[i];
 		c = p->vchan;
 		if (c) {
-			unsigned long flags;
 
-			spin_lock_irqsave(&c->vc.lock, flags);
+			spin_lock(&c->vc.lock);
 			if (c->cyclic) {
 				vchan_cyclic_callback(&p->ds_run->vd);
 			} else {
@@ -298,7 +297,7 @@ static irqreturn_t zx_dma_int_handler(int irq, void *dev_id)
 				p->ds_done = p->ds_run;
 				task = 1;
 			}
-			spin_unlock_irqrestore(&c->vc.lock, flags);
+			spin_unlock(&c->vc.lock);
 			irq_chan |= BIT(i);
 		}
 	}
-- 
2.17.1




^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR
  2018-09-11 14:31 [PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR jun qian
@ 2018-09-11 15:17 ` Lucas Stach
  0 siblings, 0 replies; 2+ messages in thread
From: Lucas Stach @ 2018-09-11 15:17 UTC (permalink / raw)
  To: jun qian, Dan Williams, Vinod Koul, Jun Nie, Baoyou Xie, Shawn Guo
  Cc: dmaengine, Barry song, linux-kernel, linux-arm-kernel

Am Dienstag, den 11.09.2018, 07:31 -0700 schrieb jun qian:
> As you are already in ISR, it is unnecessary to call
> spin_lock_irqsave.

As the IRQ in this driver isn't marked with IRQF_NO_THREAD, this is
going to blow up if the kernel is booted with the "threadirqs" command
line argument.

Regards,
Lucas

> Signed-off-by: jun qian <hangdianqj@163.com>
> Cc: Barry song <21cnbao@gmail.com>
> ---
>  drivers/dma/zx_dma.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/dma/zx_dma.c b/drivers/dma/zx_dma.c
> index 2571bc7693df..111ab2db83b1 100644
> --- a/drivers/dma/zx_dma.c
> +++ b/drivers/dma/zx_dma.c
> @@ -288,9 +288,8 @@ static irqreturn_t zx_dma_int_handler(int irq,
> void *dev_id)
>  		p = &d->phy[i];
>  		c = p->vchan;
>  		if (c) {
> -			unsigned long flags;
>  
> -			spin_lock_irqsave(&c->vc.lock, flags);
> +			spin_lock(&c->vc.lock);
>  			if (c->cyclic) {
>  				vchan_cyclic_callback(&p->ds_run-
> >vd);
>  			} else {
> @@ -298,7 +297,7 @@ static irqreturn_t zx_dma_int_handler(int irq,
> void *dev_id)
>  				p->ds_done = p->ds_run;
>  				task = 1;
>  			}
> -			spin_unlock_irqrestore(&c->vc.lock, flags);
> +			spin_unlock(&c->vc.lock);
>  			irq_chan |= BIT(i);
>  		}
>  	}

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2018-09-11 15:17 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-11 14:31 [PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR jun qian
2018-09-11 15:17 ` Lucas Stach

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).