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@xxxxxxx>
> Cc: Barry song <21cnbao@xxxxxxxxx>
> ---
> Âdrivers/dma/zx_dma.c | 5 ++---
> Â1 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)
> Â		p = &d->phy[i];
> Â		c = p->vchan;
> Â		if (c) {
> -			unsigned long flags;
> Â
> -			spin_lock_irqsave(&c->vc.lock, flags);
> +			spin_lock(&c->vc.lock);
> Â			if (c->cyclic) {
> Â				vchan_cyclic_callback(&p->ds_run-
> >vd);
> Â			} else {
> @@ -298,7 +297,7 @@ static irqreturn_t zx_dma_int_handler(int irq,
> void *dev_id)
> Â				p->ds_done = p->ds_run;
> Â				task = 1;
> Â			}
> -			spin_unlock_irqrestore(&c->vc.lock, flags);
> +			spin_unlock(&c->vc.lock);
> Â			irq_chan |= BIT(i);
> Â		}
> Â	}