From 45ae4a5220a43ae79dacb69054a2c7928dd91c94 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 10 Oct 2016 08:28:26 -0300 Subject: [PATCH] [media] cpia2_usb: don't use stack for DMA The USB control messages require DMA to work. We cannot pass a stack-allocated buffer, as it is not warranted that the stack would be into a DMA enabled area. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/cpia2/cpia2_usb.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c index 13620cd..e9100a2 100644 --- a/drivers/media/usb/cpia2/cpia2_usb.c +++ b/drivers/media/usb/cpia2/cpia2_usb.c @@ -545,18 +545,30 @@ static void free_sbufs(struct camera_data *cam) static int write_packet(struct usb_device *udev, u8 request, u8 * registers, u16 start, size_t size) { + unsigned char *buf; + int ret; + if (!registers || size <= 0) return -EINVAL; - return usb_control_msg(udev, + buf = kmalloc(size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + memcpy(buf, registers, size); + + ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), request, USB_TYPE_VENDOR | USB_RECIP_DEVICE, start, /* value */ 0, /* index */ - registers, /* buffer */ + buf, /* buffer */ size, HZ); + + kfree(buf); + return ret; } /**************************************************************************** @@ -567,18 +579,32 @@ static int write_packet(struct usb_device *udev, static int read_packet(struct usb_device *udev, u8 request, u8 * registers, u16 start, size_t size) { + unsigned char *buf; + int ret; + if (!registers || size <= 0) return -EINVAL; - return usb_control_msg(udev, + buf = kmalloc(size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), request, USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_DEVICE, start, /* value */ 0, /* index */ - registers, /* buffer */ + buf, /* buffer */ size, HZ); + + if (ret >= 0) + memcpy(registers, buf, size); + + kfree(buf); + + return ret; } /****************************************************************************** -- 2.7.4