[NET]: Fix NAPI completion handling in some drivers.
In order for the list handling in net_rx_action() to be
correct, drivers must follow certain rules as stated by
this comment in net_rx_action():
/* Drivers must not modify the NAPI state if they
* consume the entire weight. In such cases this code
* still "owns" the NAPI instance and therefore can
* move the instance around on the list at-will.
*/
A few drivers do not do this because they mix the budget checks
with reading hardware state, resulting in crashes like the one
reported by takano@axe-inc.co.jp.
BNX2 and TG3 are taken care of here, SKY2 fix is from Stephen
Hemminger.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index d2b30fb..a402b5c 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -3555,12 +3555,9 @@
return received;
}
-static int tg3_poll(struct napi_struct *napi, int budget)
+static int tg3_poll_work(struct tg3 *tp, int work_done, int budget)
{
- struct tg3 *tp = container_of(napi, struct tg3, napi);
- struct net_device *netdev = tp->dev;
struct tg3_hw_status *sblk = tp->hw_status;
- int work_done = 0;
/* handle link change and other phy events */
if (!(tp->tg3_flags &
@@ -3578,11 +3575,8 @@
/* run TX completion thread */
if (sblk->idx[0].tx_consumer != tp->tx_cons) {
tg3_tx(tp);
- if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING)) {
- netif_rx_complete(netdev, napi);
- schedule_work(&tp->reset_task);
+ if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING))
return 0;
- }
}
/* run RX thread, within the bounds set by NAPI.
@@ -3590,21 +3584,46 @@
* code synchronizes with tg3->napi.poll()
*/
if (sblk->idx[0].rx_producer != tp->rx_rcb_ptr)
- work_done = tg3_rx(tp, budget);
+ work_done += tg3_rx(tp, budget - work_done);
- if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) {
- tp->last_tag = sblk->status_tag;
- rmb();
- } else
- sblk->status &= ~SD_STATUS_UPDATED;
+ return work_done;
+}
- /* if no more work, tell net stack and NIC we're done */
- if (!tg3_has_work(tp)) {
- netif_rx_complete(netdev, napi);
- tg3_restart_ints(tp);
+static int tg3_poll(struct napi_struct *napi, int budget)
+{
+ struct tg3 *tp = container_of(napi, struct tg3, napi);
+ int work_done = 0;
+
+ while (1) {
+ work_done = tg3_poll_work(tp, work_done, budget);
+
+ if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING))
+ goto tx_recovery;
+
+ if (unlikely(work_done >= budget))
+ break;
+
+ if (likely(!tg3_has_work(tp))) {
+ struct tg3_hw_status *sblk = tp->hw_status;
+
+ if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) {
+ tp->last_tag = sblk->status_tag;
+ rmb();
+ } else
+ sblk->status &= ~SD_STATUS_UPDATED;
+
+ netif_rx_complete(tp->dev, napi);
+ tg3_restart_ints(tp);
+ break;
+ }
}
return work_done;
+
+tx_recovery:
+ netif_rx_complete(tp->dev, napi);
+ schedule_work(&tp->reset_task);
+ return 0;
}
static void tg3_irq_quiesce(struct tg3 *tp)