RE: [PATCH] idxd: avoid deadlock in process_misc_interrupts()

[Yu, Fenghua]

Hi, Jerry,

> idxd_device_clear_state() now grabs the idxd->dev_lock itself, so don't grab the
> lock prior to calling it.
> 
> This was seen in testing after dmar fault occurred on system, resulting in lockup
> stack traces.
> 

Please add Fixes: cf4ac3fef338 ...

> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> ---
>  drivers/dma/idxd/irq.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c index
> 743ead5ebc57..5b9921475be6 100644
> --- a/drivers/dma/idxd/irq.c
> +++ b/drivers/dma/idxd/irq.c
> @@ -324,13 +324,11 @@ static int process_misc_interrupts(struct idxd_device
> *idxd, u32 cause)
>  			idxd->state = IDXD_DEV_HALTED;
>  			idxd_wqs_quiesce(idxd);
>  			idxd_wqs_unmap_portal(idxd);
> -			spin_lock(&idxd->dev_lock);
>  			idxd_device_clear_state(idxd);
>  			dev_err(&idxd->pdev->dev,
>  				"idxd halted, need %s.\n",
>  				gensts.reset_type == IDXD_DEVICE_RESET_FLR ?
>  				"FLR" : "system reset");
> -			spin_unlock(&idxd->dev_lock);
>  			return -ENXIO;
>  		}
>  	}
> --
> 2.37.2

Thanks.

-Fenghua