tg3: Workaround tagged status update bug

On rare occasions, writing the tag to the interrupt mailbox does not
reenable interrupts.  This patch fixes the problem by reissuing the
mailbox update.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@conan.davemloft.net>

2 files changed, 40 insertions, 1 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index aa1d1defc820..46352da36a81 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -7754,6 +7754,9 @@ static void tg3_rings_reset(struct tg3 *tp)
 
         /* Disable interrupts */
         tw32_mailbox_f(tp->napi[0].int_mbox, 1);
+        tp->napi[0].chk_msi_cnt = 0;
+        tp->napi[0].last_rx_cons = 0;
+        tp->napi[0].last_tx_cons = 0;
 
         /* Zero mailbox registers. */
         if (tg3_flag(tp, SUPPORT_MSIX)) {
@@ -7764,6 +7767,9 @@ static void tg3_rings_reset(struct tg3 *tp)
                                 tw32_mailbox(tp->napi[i].prodmbox, 0);
                         tw32_rx_mbox(tp->napi[i].consmbox, 0);
                         tw32_mailbox_f(tp->napi[i].int_mbox, 1);
+                        tp->napi[0].chk_msi_cnt = 0;
+                        tp->napi[i].last_rx_cons = 0;
+                        tp->napi[i].last_tx_cons = 0;
                 }
                 if (!tg3_flag(tp, ENABLE_TSS))
                         tw32_mailbox(tp->napi[0].prodmbox, 0);
@@ -8819,6 +8825,30 @@ static void tg3_periodic_fetch_stats(struct tg3 *tp)
         TG3_STAT_ADD32(&sp->rx_errors, RCVLPC_IN_ERRORS_CNT);
 }
 
+static void tg3_chk_missed_msi(struct tg3 *tp)
+{
+        u32 i;
+
+        for (i = 0; i < tp->irq_cnt; i++) {
+                struct tg3_napi *tnapi = &tp->napi[i];
+
+                if (tg3_has_work(tnapi)) {
+                        if (tnapi->last_rx_cons == tnapi->rx_rcb_ptr &&
+                            tnapi->last_tx_cons == tnapi->tx_cons) {
+                                if (tnapi->chk_msi_cnt < 1) {
+                                        tnapi->chk_msi_cnt++;
+                                        return;
+                                }
+                                tw32_mailbox(tnapi->int_mbox,
+                                             tnapi->last_tag << 24);
+                        }
+                }
+                tnapi->chk_msi_cnt = 0;
+                tnapi->last_rx_cons = tnapi->rx_rcb_ptr;
+                tnapi->last_tx_cons = tnapi->tx_cons;
+        }
+}
+
 static void tg3_timer(unsigned long __opaque)
 {
         struct tg3 *tp = (struct tg3 *) __opaque;
@@ -8828,6 +8858,10 @@ static void tg3_timer(unsigned long __opaque)
 
         spin_lock(&tp->lock);
 
+        if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717 ||
+            GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_57765)
+                tg3_chk_missed_msi(tp);
+
         if (!tg3_flag(tp, TAGGED_STATUS)) {
                 /* All of this garbage is because when using non-tagged
                  * IRQ status the mailbox/status_block protocol the chip
@@ -9303,7 +9337,9 @@ static int tg3_open(struct net_device *dev)
                 tg3_halt(tp, RESET_KIND_SHUTDOWN, 1);
                 tg3_free_rings(tp);
         } else {
-                if (tg3_flag(tp, TAGGED_STATUS))
+                if (tg3_flag(tp, TAGGED_STATUS) &&
+                        GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5717 &&
+                        GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_57765)
                         tp->timer_offset = HZ;
                 else
                         tp->timer_offset = HZ / 10;
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 5b3d2f34da7a..3c113c1e9d35 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2800,6 +2800,7 @@ struct tg3_napi {
         struct tg3                      *tp;
         struct tg3_hw_status            *hw_status;
 
+        u32                             chk_msi_cnt;
         u32                             last_tag;
         u32                             last_irq_tag;
         u32                             int_mbox;
@@ -2807,6 +2808,7 @@ struct tg3_napi {
 
         u32                             consmbox ____cacheline_aligned;
         u32                             rx_rcb_ptr;
+        u32                             last_rx_cons;
         u16                             *rx_rcb_prod_idx;
         struct tg3_rx_prodring_set      prodring;
         struct tg3_rx_buffer_desc       *rx_rcb;
@@ -2814,6 +2816,7 @@ struct tg3_napi {
         u32                             tx_prod ____cacheline_aligned;
         u32                             tx_cons;
         u32                             tx_pending;
+        u32                             last_tx_cons;
         u32                             prodmbox;
         struct tg3_tx_buffer_desc       *tx_ring;
         struct ring_info                *tx_buffers;