USB CDC NCM: tx_fixup() race condition fix
- tx_fixup() can be called from either timer callback or from xmit()
in usbnet, so spinlock is added to avoid concurrency-related problem.
- minor correction due to checkpatch warning for some line over 80
chars after previous patch was applied.
Signed-off-by: Alexey Orishko <alexey.orishko@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d776c4a..04e8ce1 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -54,7 +54,7 @@
#include <linux/usb/usbnet.h>
#include <linux/usb/cdc.h>
-#define DRIVER_VERSION "30-Nov-2010"
+#define DRIVER_VERSION "17-Jan-2011"
/* CDC NCM subclass 3.2.1 */
#define USB_CDC_NCM_NDP16_LENGTH_MIN 0x10
@@ -868,15 +868,19 @@
if (ctx->tx_timer_pending != 0) {
ctx->tx_timer_pending--;
restart = 1;
- } else
+ } else {
restart = 0;
+ }
spin_unlock(&ctx->mtx);
- if (restart)
+ if (restart) {
+ spin_lock(&ctx->mtx);
cdc_ncm_tx_timeout_start(ctx);
- else if (ctx->netdev != NULL)
+ spin_unlock(&ctx->mtx);
+ } else if (ctx->netdev != NULL) {
usbnet_start_xmit(NULL, ctx->netdev);
+ }
}
static struct sk_buff *
@@ -900,7 +904,6 @@
skb_out = cdc_ncm_fill_tx_frame(ctx, skb);
if (ctx->tx_curr_skb != NULL)
need_timer = 1;
- spin_unlock(&ctx->mtx);
/* Start timer, if there is a remaining skb */
if (need_timer)
@@ -908,6 +911,8 @@
if (skb_out)
dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
+
+ spin_unlock(&ctx->mtx);
return skb_out;
error:
@@ -1020,8 +1025,8 @@
if (((offset + temp) > actlen) ||
(temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) {
pr_debug("invalid frame detected (ignored)"
- "offset[%u]=%u, length=%u, skb=%p\n",
- x, offset, temp, skb_in);
+ "offset[%u]=%u, length=%u, skb=%p\n",
+ x, offset, temp, skb_in);
if (!x)
goto error;
break;