usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC

[ 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.

Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Tested-by: James Grant <jamesg@zaltys.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
index 00b5006..90d24f6 100644 (file)
--- a/drivers/usb/gadget/udc/lpc32xx_udc.c
+++ b/drivers/usb/gadget/udc/lpc32xx_udc.c
@@ -964,8 +964,7 @@ 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;