Re: [PATCH 5.1 29/96] usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC

Pavel Machek
2019-07-10T09:59:59Z

On Mon 2019-07-08 17:13:01, Greg Kroah-Hartman wrote:
> [ Upstream commit fbc318afadd6e7ae2252d6158cf7d0c5a2132f7d ]
>
> 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.

GFP_ATOMIC allocations can and do fail, but I don't see any explicit error handling.

Can someone check everything is ok?

Thanks,
Pavel

> diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
> index b0781771704e..eafc2a00c96a 100644
> --- a/drivers/usb/gadget/udc/lpc32xx_udc.c
> +++ b/drivers/usb/gadget/udc/lpc32xx_udc.c
> @@ -922,8 +922,7 @@ 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;
>
> --
> 2.20.1
>
>

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