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* [PATCH v2] usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC
@ 2019-05-22 12:07 Alexandre Belloni
  2019-05-22 15:02 ` Sylvain Lemieux
  0 siblings, 1 reply; 2+ messages in thread
From: Alexandre Belloni @ 2019-05-22 12:07 UTC (permalink / raw)
  To: Felipe Balbi, Vladimir Zapolskiy, Greg Kroah-Hartman
  Cc: Alexandre Belloni, linux-usb, linux-kernel, Sylvain Lemieux,
	linux-arm-kernel, James Grant

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@zaltys.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---

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


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^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH v2] usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC
  2019-05-22 12:07 [PATCH v2] usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC Alexandre Belloni
@ 2019-05-22 15:02 ` Sylvain Lemieux
  0 siblings, 0 replies; 2+ messages in thread
From: Sylvain Lemieux @ 2019-05-22 15:02 UTC (permalink / raw)
  To: Alexandre Belloni
  Cc: Felipe Balbi, Greg Kroah-Hartman, linux-usb, linux-kernel,
	Vladimir Zapolskiy, moderated list:ARM PORT, James Grant

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

On Wed, May 22, 2019 at 8:07 AM Alexandre Belloni
<alexandre.belloni@bootlin.com> 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@zaltys.org>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> ---
>
> 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
>

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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2019-05-22 12:07 [PATCH v2] usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC Alexandre Belloni
2019-05-22 15:02 ` Sylvain Lemieux

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