On Tue, 21 Jun 2005, Ingo Molnar wrote:
> i'm not sure it's related to the lockup - but there is a generic bug in
> the driver, which in ns83820_tx_timeout() does:
>
> local_irq_save(flags);
> ...
> CALL do_tx_done()
>
> spin_lock_irq(&dev->tx_lock);
> ...
> spin_unlock_irq(&dev->tx_lock); // [1]
> ...
> local_irq_restore(flags); // [2]
>
> this leads to interrupts being enabled at [1], while the intention was
> to enable them at [2]. To solve this bug we can do the tx-locking in
> ns83820_tx_timeout(). (local_irq_disable() use in ns83820_tx_timeout()
> was probably SMP-unsafe too, but needs a rare race.)
>
> find the patch below - it's also included in the -50-05 -RT tree i just
> uploaded. Can you confirm that you dont get the warnings in the -50-05
> (and later) -RT kernels?
>
> Ingo
-48-37 still gave the warnings on ns83820_tx_timeout(), but otherwise ran
for a day without any lockups or loss of network or keyboard. No warnings
so far with -50-06. I'll keep you posted.
--ww <[email protected]>
> Index: drivers/net/ns83820.c
> ===================================================================
> --- drivers/net/ns83820.c.orig
> +++ drivers/net/ns83820.c
> @@ -1013,8 +1013,6 @@ static void do_tx_done(struct net_device
> struct ns83820 *dev = PRIV(ndev);
> u32 cmdsts, tx_done_idx, *desc;
>
> - spin_lock_irq(&dev->tx_lock);
> -
> dprintk("do_tx_done(%p)\n", ndev);
> tx_done_idx = dev->tx_done_idx;
> desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
> @@ -1070,7 +1068,6 @@ static void do_tx_done(struct net_device
> netif_start_queue(ndev);
> netif_wake_queue(ndev);
> }
> - spin_unlock_irq(&dev->tx_lock);
> }
>
> static void ns83820_cleanup_tx(struct ns83820 *dev)
> @@ -1371,7 +1368,9 @@ static void ns83820_do_isr(struct net_de
> * work has accumulated
> */
> if ((ISR_TXDESC | ISR_TXIDLE | ISR_TXOK | ISR_TXERR) & isr) {
> + spin_lock_irq(&dev->tx_lock);
> do_tx_done(ndev);
> + spin_unlock_irq(&dev->tx_lock);
>
> /* Disable TxOk if there are no outstanding tx packets.
> */
> @@ -1456,7 +1455,7 @@ static void ns83820_tx_timeout(struct ne
> u32 tx_done_idx, *desc;
> unsigned long flags;
>
> - local_irq_save(flags);
> + spin_lock_irqsave(&dev->tx_lock, flags);
>
> tx_done_idx = dev->tx_done_idx;
> desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
> @@ -1483,7 +1482,7 @@ static void ns83820_tx_timeout(struct ne
> ndev->name,
> tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));
>
> - local_irq_restore(flags);
> + spin_unlock_irqrestore(&dev->tx_lock, flags);
> }
>
>
-
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