Re: [PATCH 2.6.18-rc6 1/2] dllink driver: porting v1.19 to linux2.6.18-rc6

From: Arjan van de Ven
Date: Thu Sep 07 2006 - 05:17:40 EST


> @@ -335,8 +374,9 @@
> #endif
> /* Read eeprom */
> for (i = 0; i < 128; i++) {
> - ((u16 *) sromdata)[i] = le16_to_cpu (read_eeprom (ioaddr, i));
> + ((u16 *) sromdata)[i] = cpu_to_le16 (read_eeprom (ioaddr, i));
> }
> + psrom->crc = le32_to_cpu(psrom->crc);

this looks wrong, the data comes from the hw as le, so le*_to_cpu()
sounds the right direction

> @@ -401,7 +441,7 @@
> int i;
> u16 macctrl;
>
> - i = request_irq (dev->irq, &rio_interrupt, IRQF_SHARED, dev->name, dev);
> + i = request_irq (dev->irq, &rio_interrupt, SA_SHIRQ, dev->name, dev);
> if (i)
> return i;

this is backing out a fix/conversion to the new API. Bad.


>
> @@ -434,9 +474,12 @@
> writeb (0x30, ioaddr + RxDMABurstThresh);
> writeb (0x30, ioaddr + RxDMAUrgentThresh);
> writel (0x0007ffff, ioaddr + RmonStatMask);
> +
> /* clear statistics */
> clear_stats (dev);
>
> + atomic_set(&np->tx_desc_lock, 0);

I'm quite scared by this naming; it suggests home-brew locking

> dev->trans_start = jiffies;
> + tasklet_enable(&np->tx_tasklet);
> + writew(DEFAULT_INTR, ioaddr + IntEnable);
> + return;

this looks like a PCI posting bug


> -rio_free_tx (struct net_device *dev, int irq)
> +rio_free_tx (struct net_device *dev)
> {
> struct netdev_private *np = netdev_priv(dev);
> int entry = np->old_tx % TX_RING_SIZE;
> - int tx_use = 0;
> unsigned long flag = 0;
> + int irq = in_interrupt();

eeeeep

> +
> + if (atomic_read(&np->tx_desc_lock))
> + return;
> + atomic_inc(&np->tx_desc_lock);

and yes.. it is broken self made locking....
there is a nice race between the _read and the _inc here.


>
> if (irq)
> spin_lock(&np->tx_lock);
> else
> spin_lock_irqsave(&np->tx_lock, flag);

double eeeep

this is wrong to do with in_interrupt() as gating factor!
Always doing the irqsave() is fine btw



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