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Message-ID: <20190710095910.GA7413@xo-6d-61-c0.localdomain>
Date: Wed, 10 Jul 2019 11:59:10 +0200
From: Pavel Machek <pavel@....cz>
To: pavel@....cz
Cc: linux-kernel@...r.kernel.org,
Sylvain Lemieux <slemieux.tyco@...il.com>,
James Grant <jamesg@...tys.org>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
Felipe Balbi <felipe.balbi@...ux.intel.com>,
Sasha Levin <sashal@...nel.org>
Subject: Re: [PATCH 5.1 29/96] usb: gadget: udc: lpc32xx: allocate descriptor
with GFP_ATOMIC
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
>
>
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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