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

Manivannan Sadhasivam
2022-05-12T14:39:12Z

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@baikalelectronics.ru>

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

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
>

--
மணிவண்ணன் சதாசிவம்