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

From: Alexandre Belloni
Date: Wed May 22 2019 - 08:10:30 EST


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