spidernet: improve interrupt handling

We intend this patch to improve spidernet interrupt handling to be
more strict.  We had following problem and this patch solves it.

 -when CONFIG_DEBUG_SHIRQ=y, request_irq() calls handler().
 -when spider_net_open() is called, it calls request_irq() which calls
  spider_net_interrupt().
 -if some specific interrupt bit is set at this timing, it calls
  netif_rx_schedule() and spider_net_poll() is scheduled.
 -spider_net_open() calls netif_poll_enable() which clears the bit
  __LINK_STATE_RX_SCHED.
 -when spider_net_poll() is called, it calls netif_rx_complete() which
  causes BUG_ON() because __LINK_STATE_RX_SCHED is not set.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 45 insertions, 14 deletions

diff --git a/drivers/net/spider_net.c b/drivers/net/spider_net.c
index f5abb5279d4d..590b12c7246c 100644
--- a/drivers/net/spider_net.c
+++ b/drivers/net/spider_net.c
@@ -1441,11 +1441,17 @@ static void
 spider_net_handle_error_irq(struct spider_net_card *card, u32 status_reg)
 {
         u32 error_reg1, error_reg2;
+        u32 mask_reg1, mask_reg2;
         u32 i;
         int show_error = 1;
 
         error_reg1 = spider_net_read_reg(card, SPIDER_NET_GHIINT1STS);
         error_reg2 = spider_net_read_reg(card, SPIDER_NET_GHIINT2STS);
+        mask_reg1 = spider_net_read_reg(card, SPIDER_NET_GHIINT1MSK);
+        mask_reg2 = spider_net_read_reg(card,SPIDER_NET_GHIINT2MSK);
+
+        error_reg1 &= mask_reg1;
+        error_reg2 &= mask_reg2;
 
         /* check GHIINT0STS ************************************/
         if (status_reg)
@@ -1673,9 +1679,11 @@ spider_net_interrupt(int irq, void *ptr)
 {
         struct net_device *netdev = ptr;
         struct spider_net_card *card = netdev_priv(netdev);
-        u32 status_reg;
+        u32 status_reg, mask_reg;
 
         status_reg = spider_net_read_reg(card, SPIDER_NET_GHIINT0STS);
+        mask_reg = spider_net_read_reg(card, SPIDER_NET_GHIINT0MSK);
+        status_reg &= mask_reg;
 
         if (!status_reg)
                 return IRQ_NONE;
@@ -1717,6 +1725,38 @@ spider_net_poll_controller(struct net_device *netdev)
 #endif /* CONFIG_NET_POLL_CONTROLLER */
 
 /**
+ * spider_net_enable_interrupts - enable interrupts
+ * @card: card structure
+ *
+ * spider_net_enable_interrupt enables several interrupts
+ */
+static void 
+spider_net_enable_interrupts(struct spider_net_card *card)
+{
+        spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK,
+                             SPIDER_NET_INT0_MASK_VALUE);
+        spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK,
+                             SPIDER_NET_INT1_MASK_VALUE);
+        spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK,
+                             SPIDER_NET_INT2_MASK_VALUE);
+}
+
+/**
+ * spider_net_disable_interrupts - disable interrupts
+ * @card: card structure
+ *
+ * spider_net_disable_interrupts disables all the interrupts
+ */
+static void 
+spider_net_disable_interrupts(struct spider_net_card *card)
+{
+        spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, 0);
+        spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK, 0);
+        spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK, 0);
+        spider_net_write_reg(card, SPIDER_NET_GMACINTEN, 0);
+}
+
+/**
  * spider_net_init_card - initializes the card
  * @card: card structure
  *
@@ -1736,6 +1776,7 @@ spider_net_init_card(struct spider_net_card *card)
         spider_net_write_reg(card, SPIDER_NET_GMACOPEMD,
                 spider_net_read_reg(card, SPIDER_NET_GMACOPEMD) | 0x4);
 
+        spider_net_disable_interrupts(card);
 }
 
 /**
@@ -1823,14 +1864,6 @@ spider_net_enable_card(struct spider_net_card *card)
         spider_net_write_reg(card, SPIDER_NET_GMACOPEMD,
                              SPIDER_NET_OPMODE_VALUE);
 
-        /* set interrupt mask registers */
-        spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK,
-                             SPIDER_NET_INT0_MASK_VALUE);
-        spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK,
-                             SPIDER_NET_INT1_MASK_VALUE);
-        spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK,
-                             SPIDER_NET_INT2_MASK_VALUE);
-
         spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
                              SPIDER_NET_GDTBSTA);
 }
@@ -2007,6 +2040,8 @@ spider_net_open(struct net_device *netdev)
         netif_carrier_on(netdev);
         netif_poll_enable(netdev);
 
+        spider_net_enable_interrupts(card);
+
         return 0;
 
 register_int_failed:
@@ -2179,11 +2214,7 @@ spider_net_stop(struct net_device *netdev)
         del_timer_sync(&card->tx_timer);
         del_timer_sync(&card->aneg_timer);
 
-        /* disable/mask all interrupts */
-        spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, 0);
-        spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK, 0);
-        spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK, 0);
-        spider_net_write_reg(card, SPIDER_NET_GMACINTEN, 0);
+        spider_net_disable_interrupts(card);
 
         free_irq(netdev->irq, netdev);