David S. Miller wrote:
> From: Geoff Levand <[EMAIL PROTECTED]>
> Date: Thu, 25 Aug 2005 22:13:57 -0700
>
>
>>@@ -970,7 +970,8 @@
>> /* gem_interrupt is safe to reentrance so no need
>> * to disable_irq here.
>> */
>>- gem_interrupt(dev->irq, dev, NULL);
>>+ if(gem_interrupt(dev->irq, dev, NULL) == IRQ_NONE)
>>+ __netif_rx_schedule(dev);
>> }
>> #endif
>
>
> It might be cleaner to just open-code the parts of gem_interrupt()
> we want, making the necessary modifications to make sure
> __netif_rx_schedule() occurs and a snapshot of gp->gem_status
> is always sampled.
>
I took a look at your suggestion, but it turned ugly, as there
are many code paths to gem_poll(), and the netif routines
don't export enough information to determine the state from
inside gem_poll(). My solution is to keep a state variable
in the device structure. This should give a 100% proper
solution (my original patch didn't cover all cases).
-Geoff
This fixes a major bug in the Sun GEM Ether
driver's netpoll implementation. When using
kgdb over Ether the condition easily arises
where the bug is hit.
The problem is that gem_poll() expects an rx softnet_data
structure to have been allocated (via __netif_rx_schedule())
prior to its being called. The existing gem driver code
uses gem_interrupt() to set things up for gem_poll(),
but unfortunately, gem_interrupt() doesn't know about
this, and so doesn't allocate the required structure
when it finds no bits set in the interrupt status
register. gem_poll() then move on its way and tries to
delete the non-existent softnet_data structure.
Signed-off-by: Geoff Levand <[EMAIL PROTECTED]>
Index: linux-2.6.12/drivers/net/sungem.c
===================================================================
--- linux-2.6.12.orig/drivers/net/sungem.c 2005-08-26 10:27:07.000000000
-0700
+++ linux-2.6.12/drivers/net/sungem.c 2005-08-26 17:38:54.000000000 -0700
@@ -885,6 +885,15 @@
*/
spin_lock_irqsave(&gp->lock, flags);
+ /*
+ * This takes care of the case when gem_interrupt()
+ * failed to call __netif_rx_schedule().
+ */
+ if(!gp->rx_scheduled) {
+ netif_rx_schedule_prep(dev);
+ __netif_rx_schedule(dev);
+ }
+
do {
int work_to_do, work_done;
@@ -922,6 +931,7 @@
} while (gp->status & GREG_STAT_NAPI);
__netif_rx_complete(dev);
+ gp->rx_scheduled = 0;
gem_enable_ints(gp);
spin_unlock_irqrestore(&gp->lock, flags);
@@ -945,14 +955,15 @@
if (netif_rx_schedule_prep(dev)) {
u32 gem_status = readl(gp->regs + GREG_STAT);
+ gp->status = gem_status;
- if (gem_status == 0) {
+ if ((gem_status & ~GREG_STAT_TXNR) == 0) {
spin_unlock_irqrestore(&gp->lock, flags);
return IRQ_NONE;
}
- gp->status = gem_status;
gem_disable_ints(gp);
__netif_rx_schedule(dev);
+ gp->rx_scheduled = 1;
}
spin_unlock_irqrestore(&gp->lock, flags);
@@ -3047,6 +3058,7 @@
gp->lstate = link_down;
gp->timer_ticks = 0;
+ gp->rx_scheduled = 0;
netif_carrier_off(dev);
gp->regs = ioremap(gemreg_base, gemreg_len);
Index: linux-2.6.12/drivers/net/sungem.h
===================================================================
--- linux-2.6.12.orig/drivers/net/sungem.h 2005-08-26 10:27:07.000000000
-0700
+++ linux-2.6.12/drivers/net/sungem.h 2005-08-26 16:54:34.000000000 -0700
@@ -1020,7 +1020,7 @@
struct gem_init_block *init_block;
struct sk_buff *rx_skbs[RX_RING_SIZE];
- struct sk_buff *tx_skbs[RX_RING_SIZE];
+ struct sk_buff *tx_skbs[TX_RING_SIZE];
dma_addr_t gblock_dvma;
struct pci_dev *pdev;
@@ -1028,6 +1028,7 @@
#ifdef CONFIG_PPC_PMAC
struct device_node *of_node;
#endif
+ int rx_scheduled;
};
#define found_mii_phy(gp) ((gp->phy_type == phy_mii_mdio0 || gp->phy_type ==
phy_mii_mdio1) \
-
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