diff options
| author | Michael Chan <mchan@broadcom.com> | 2012-03-21 15:38:33 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-03-21 21:57:36 -0400 |
| commit | 7ae5289017e5ed5514b2603d157fb54c058a3c82 (patch) | |
| tree | 3ab4c34f95aced979df8ad5e7be721996f5911b1 /drivers/net | |
| parent | 5676cc7bfe1e388e87843f71daa229610385b41e (diff) | |
| download | linux-7ae5289017e5ed5514b2603d157fb54c058a3c82.tar.gz linux-7ae5289017e5ed5514b2603d157fb54c058a3c82.tar.bz2 linux-7ae5289017e5ed5514b2603d157fb54c058a3c82.zip | |
tg3: Fix RSS ring refill race condition
The RSS feature in tg3 hardware has only one rx producer ring for all
RSS rings. NAPI vector 1 is special and handles the refilling of the
rx producer ring on behalf of all RSS rings. There is a race condition
between these RSS NAPIs and the NAPI[1]. If NAPI[1] finishes checking
for refill and then another RSS ring empties the rx producer ring
before NAPI[1] exits NAPI, the chip will be completely out of SKBs in
the rx producer ring.
We fix this by adding a flag tp->rx_refill and rely on napi_schedule()/
napi_complete() to help synchronize it to close the race condition.
Update driver version to 3.123.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/broadcom/tg3.c | 25 | ||||
| -rw-r--r-- | drivers/net/ethernet/broadcom/tg3.h | 1 |
2 files changed, 23 insertions, 3 deletions
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index b0657466041d..7b71387cf93c 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -89,10 +89,10 @@ static inline void _tg3_flag_clear(enum TG3_FLAGS flag, unsigned long *bits) #define DRV_MODULE_NAME "tg3" #define TG3_MAJ_NUM 3 -#define TG3_MIN_NUM 122 +#define TG3_MIN_NUM 123 #define DRV_MODULE_VERSION \ __stringify(TG3_MAJ_NUM) "." __stringify(TG3_MIN_NUM) -#define DRV_MODULE_RELDATE "December 7, 2011" +#define DRV_MODULE_RELDATE "March 21, 2012" #define RESET_KIND_SHUTDOWN 0 #define RESET_KIND_INIT 1 @@ -5953,8 +5953,10 @@ next_pkt_nopost: tpr->rx_std_prod_idx = std_prod_idx & tp->rx_std_ring_mask; tpr->rx_jmb_prod_idx = jmb_prod_idx & tp->rx_jmb_ring_mask; - if (tnapi != &tp->napi[1]) + if (tnapi != &tp->napi[1]) { + tp->rx_refill = true; napi_schedule(&tp->napi[1].napi); + } } return received; @@ -6134,6 +6136,7 @@ static int tg3_poll_work(struct tg3_napi *tnapi, int work_done, int budget) u32 std_prod_idx = dpr->rx_std_prod_idx; u32 jmb_prod_idx = dpr->rx_jmb_prod_idx; + tp->rx_refill = false; for (i = 1; i < tp->irq_cnt; i++) err |= tg3_rx_prodring_xfer(tp, dpr, &tp->napi[i].prodring); @@ -6197,9 +6200,25 @@ static int tg3_poll_msix(struct napi_struct *napi, int budget) /* check for RX/TX work to do */ if (likely(sblk->idx[0].tx_consumer == tnapi->tx_cons && *(tnapi->rx_rcb_prod_idx) == tnapi->rx_rcb_ptr)) { + + /* This test here is not race free, but will reduce + * the number of interrupts by looping again. + */ + if (tnapi == &tp->napi[1] && tp->rx_refill) + continue; + napi_complete(napi); /* Reenable interrupts. */ tw32_mailbox(tnapi->int_mbox, tnapi->last_tag << 24); + + /* This test here is synchronized by napi_schedule() + * and napi_complete() to close the race condition. + */ + if (unlikely(tnapi == &tp->napi[1] && tp->rx_refill)) { + tw32(HOSTCC_MODE, tp->coalesce_mode | + HOSTCC_MODE_ENABLE | + tnapi->coal_now); + } mmiowb(); break; } diff --git a/drivers/net/ethernet/broadcom/tg3.h b/drivers/net/ethernet/broadcom/tg3.h index 66bcfca55261..93865f899a4f 100644 --- a/drivers/net/ethernet/broadcom/tg3.h +++ b/drivers/net/ethernet/broadcom/tg3.h @@ -3007,6 +3007,7 @@ struct tg3 { u32 rx_std_max_post; u32 rx_offset; u32 rx_pkt_map_sz; + bool rx_refill; /* begin "everything else" cacheline(s) section */ |