Re: [PATCH v2] usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC

[Sylvain Lemieux]

Acked-by: Sylvain Lemieux <slemieux.tyco@xxxxxxxxx>

On Wed, May 22, 2019 at 8:07 AM Alexandre Belloni
<alexandre.belloni@xxxxxxxxxxx> wrote:
>
> Gadget drivers may queue request in interrupt context. This would lead to
> a descriptor allocation in that context. In that case we would hit
> BUG_ON(in_interrupt()) in __get_vm_area_node.
>
> Also remove the unnecessary cast.
>
> Tested-by: James Grant <jamesg@xxxxxxxxxx>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> ---
>
> Changes in v2:
>  - remove unnecessary cast as pointed by Joe Perches
>  - Collected tested-by
>
>  drivers/usb/gadget/udc/lpc32xx_udc.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
> index d8f1c60793ed..2719194ebf42 100644
> --- a/drivers/usb/gadget/udc/lpc32xx_udc.c
> +++ b/drivers/usb/gadget/udc/lpc32xx_udc.c
> @@ -937,8 +937,7 @@ static struct lpc32xx_usbd_dd_gad *udc_dd_alloc(struct lpc32xx_udc *udc)
>         dma_addr_t                      dma;
>         struct lpc32xx_usbd_dd_gad      *dd;
>
> -       dd = (struct lpc32xx_usbd_dd_gad *) dma_pool_alloc(
> -                       udc->dd_cache, (GFP_KERNEL | GFP_DMA), &dma);
> +       dd = dma_pool_alloc(udc->dd_cache, GFP_ATOMIC | GFP_DMA, &dma);
>         if (dd)
>                 dd->this_dma = dma;
>
> --
> 2.21.0
>