[PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR

[PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR

[jun qian]

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

Re: [PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR

[Lucas Stach]

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);
>  		}
>  	}