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

[Joe Perches]

On Fri, 2019-05-10 at 14:42 +0200, Alexandre Belloni 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.
[]
> diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
[]
> @@ -938,7 +938,7 @@ static struct lpc32xx_usbd_dd_gad *udc_dd_alloc(struct lpc32xx_udc *udc)
>  	struct lpc32xx_usbd_dd_gad	*dd;
>  
>  	dd = (struct lpc32xx_usbd_dd_gad *) dma_pool_alloc(
> -			udc->dd_cache, (GFP_KERNEL | GFP_DMA), &dma);
> +			udc->dd_cache, (GFP_ATOMIC | GFP_DMA), &dma);

trivia:

This could fit nicely on a single line without the
unnecessary cast and the unnecessary parentheses
around the GFP_ types.