Re: [PATCH v2 03/26] dmaengine: dw-edma: Release requested IRQs on failure

[Manivannan Sadhasivam]

On Wed, May 04, 2022 at 01:50:41AM +0300, Serge Semin wrote:
> From very beginning of the DW eDMA driver live in the kernel the method
> dw_edma_irq_request() hasn't been designed quite correct. In case if the
> request_irq() method fails to initialize the IRQ handler at some point the
> previously requested IRQs will be left initialized. It's prune to errors
> up to the system crash. Let's fix that by releasing the previously
> requested IRQs in the cleanup-on-error path of the dw_edma_irq_request()
> function.
> 
> Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>

Thanks,
Mani

> 
> ---
> 
> Changelog v2:
> - This is a new patch added in v2 iteration of the series.
> ---
>  drivers/dma/dw-edma/dw-edma-core.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index 07f756479663..04efcb16d13d 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -899,10 +899,8 @@ static int dw_edma_irq_request(struct dw_edma *dw,
>  						dw_edma_interrupt_read,
>  					  IRQF_SHARED, dw->name,
>  					  &dw->irq[i]);
> -			if (err) {
> -				dw->nr_irqs = i;
> -				return err;
> -			}
> +			if (err)
> +				goto err_irq_free;
>  
>  			if (irq_get_msi_desc(irq))
>  				get_cached_msi_msg(irq, &dw->irq[i].msi);
> @@ -911,6 +909,14 @@ static int dw_edma_irq_request(struct dw_edma *dw,
>  		dw->nr_irqs = i;
>  	}
>  
> +	return 0;
> +
> +err_irq_free:
> +	for  (i--; i >= 0; i--) {
> +		irq = chip->ops->irq_vector(dev, i);
> +		free_irq(irq, &dw->irq[i]);
> +	}
> +
>  	return err;
>  }
>  
> -- 
> 2.35.1
> 

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