V4L/DVB (13324): gspca - pac7302/pac7311: Handle return value of usb_control_msg().

The function usb_control_msg() can return error any time so at least
warn the user if an error happens. No message is printed in case of
normal operation.

Signed-off-by: Marton Nemeth <nm127@freemail.hu>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 21 insertions, 3 deletions

diff --git a/drivers/media/video/gspca/pac7302.c b/drivers/media/video/gspca/pac7302.c
index 228b414709f7..60d1a31f5307 100644
--- a/drivers/media/video/gspca/pac7302.c
+++ b/drivers/media/video/gspca/pac7302.c
@@ -335,14 +335,20 @@ static void reg_w_buf(struct gspca_dev *gspca_dev,
                   __u8 index,
                   const char *buffer, int len)
 {
+        int ret;
+
         memcpy(gspca_dev->usb_buf, buffer, len);
-        usb_control_msg(gspca_dev->dev,
+        ret = usb_control_msg(gspca_dev->dev,
                         usb_sndctrlpipe(gspca_dev->dev, 0),
                         1,              /* request */
                         USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                         0,              /* value */
                         index, gspca_dev->usb_buf, len,
                         500);
+        if (ret < 0)
+                PDEBUG(D_ERR, "reg_w_buf(): "
+                "Failed to write registers to index 0x%x, error %i",
+                index, ret);
 }
 
 
@@ -350,13 +356,19 @@ static void reg_w(struct gspca_dev *gspca_dev,
                   __u8 index,
                   __u8 value)
 {
+        int ret;
+
         gspca_dev->usb_buf[0] = value;
-        usb_control_msg(gspca_dev->dev,
+        ret = usb_control_msg(gspca_dev->dev,
                         usb_sndctrlpipe(gspca_dev->dev, 0),
                         0,                      /* request */
                         USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                         0, index, gspca_dev->usb_buf, 1,
                         500);
+        if (ret < 0)
+                PDEBUG(D_ERR, "reg_w(): "
+                "Failed to write register to index 0x%x, value 0x%x, error %i",
+                index, value, ret);
 }
 
 static void reg_w_seq(struct gspca_dev *gspca_dev,
@@ -373,17 +385,23 @@ static void reg_w_page(struct gspca_dev *gspca_dev,
                         const __u8 *page, int len)
 {
         int index;
+        int ret;
 
         for (index = 0; index < len; index++) {
                 if (page[index] == SKIP)                /* skip this index */
                         continue;
                 gspca_dev->usb_buf[0] = page[index];
-                usb_control_msg(gspca_dev->dev,
+                ret = usb_control_msg(gspca_dev->dev,
                                 usb_sndctrlpipe(gspca_dev->dev, 0),
                                 0,                      /* request */
                         USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                 0, index, gspca_dev->usb_buf, 1,
                                 500);
+                if (ret < 0)
+                        PDEBUG(D_ERR, "reg_w_page(): "
+                        "Failed to write register to index 0x%x, "
+                        "value 0x%x, error %i",
+                        index, page[index], ret);
         }
 }