[media] stk1160: Try to continue with fewer transfer buffers

Many people are trying to use stk1160 on low memory devices.
Instead of failing if one allocation fails, we allow the driver
to continue working if fewer transfer buffers are available.

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/media/usb/stk1160/stk1160-video.c b/drivers/media/usb/stk1160/stk1160-video.c
index 8bdfb0275313..fa3671de02aa 100644
--- a/drivers/media/usb/stk1160/stk1160-video.c
+++ b/drivers/media/usb/stk1160/stk1160-video.c
@@ -475,7 +475,11 @@ int stk1160_alloc_isoc(struct stk1160 *dev)
 		if (!dev->isoc_ctl.transfer_buffer[i]) {
 			stk1160_err("cannot alloc %d bytes for tx[%d] buffer\n",
 				sb_size, i);
-			goto free_i_bufs;
+
+			/* Not enough transfer buffers, so just give up */
+			if (i < STK1160_MIN_BUFS)
+				goto free_i_bufs;
+			goto nomore_tx_bufs;
 		}
 		memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
 
@@ -506,13 +510,28 @@ int stk1160_alloc_isoc(struct stk1160 *dev)
 		}
 	}
 
-	stk1160_dbg("urbs allocated\n");
+	stk1160_dbg("%d urbs allocated\n", num_bufs);
 
 	/* At last we can say we have some buffers */
 	dev->isoc_ctl.num_bufs = num_bufs;
 
 	return 0;
 
+nomore_tx_bufs:
+	/*
+	 * Failed to allocate desired buffer count. However, we may have
+	 * enough to work fine, so we just free the extra urb,
+	 * store the allocated count and keep going, fingers crossed!
+	 */
+	usb_free_urb(dev->isoc_ctl.urb[i]);
+	dev->isoc_ctl.urb[i] = NULL;
+
+	stk1160_warn("%d urbs allocated. Trying to continue...\n", i - 1);
+
+	dev->isoc_ctl.num_bufs = i - 1;
+
+	return 0;
+
 free_i_bufs:
 	/* Save the allocated buffers so far, so we can properly free them */
 	dev->isoc_ctl.num_bufs = i+1;