Re: [PATCH] use mmiowb in via-rhine

[Matt Mackall]

On Wed, Jan 19, 2005 at 12:22:20PM -0800, Matt Mackall wrote:
> Use the generic PCI memory barrier. Test-compiled.

Ignore that, doesn't work as I thought. mmiowb prevents write
reordering on multiple CPUs like Altix but doesn't prevent posting.
Perhaps another barrier is needed.
 
> Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
> 
> Index: bk/drivers/net/via-rhine.c
> ===================================================================
> --- bk.orig/drivers/net/via-rhine.c	2005-01-19 12:06:52.283455936 -0800
> +++ bk/drivers/net/via-rhine.c	2005-01-19 12:18:02.536561976 -0800
> @@ -351,9 +351,6 @@
>   * indicator. In addition, Tx and Rx buffers need to 4 byte aligned.
>   */
>  
> -/* Beware of PCI posted writes */
> -#define IOSYNC	do { ioread8(ioaddr + StationAddr); } while (0)
> -
>  static struct pci_device_id rhine_pci_tbl[] =
>  {
>  	{0x1106, 0x3043, PCI_ANY_ID, PCI_ANY_ID, 0, 0, }, /* VT86C100A */
> @@ -596,7 +593,7 @@
>  	void __iomem *ioaddr = rp->base;
>  
>  	iowrite8(Cmd1Reset, ioaddr + ChipCmd1);
> -	IOSYNC;
> +	mmiowb();
>  
>  	if (ioread8(ioaddr + ChipCmd1) & Cmd1Reset) {
>  		printk(KERN_INFO "%s: Reset not complete yet. "
> @@ -1305,7 +1302,7 @@
>  	/* Wake the potentially-idle transmit channel */
>  	iowrite8(ioread8(ioaddr + ChipCmd1) | Cmd1TxDemand,
>  	       ioaddr + ChipCmd1);
> -	IOSYNC;
> +	mmiowb();
>  
>  	if (rp->cur_tx == rp->dirty_tx + TX_QUEUE_LEN)
>  		netif_stop_queue(dev);
> @@ -1339,7 +1336,7 @@
>  		if (intr_status & IntrTxDescRace)
>  			iowrite8(0x08, ioaddr + IntrStatus2);
>  		iowrite16(intr_status & 0xffff, ioaddr + IntrStatus);
> -		IOSYNC;
> +		mmiowb();
>  
>  		if (debug > 4)
>  			printk(KERN_DEBUG "%s: Interrupt, status %8.8x.\n",
> @@ -1602,7 +1599,7 @@
>  		       ioaddr + ChipCmd);
>  		iowrite8(ioread8(ioaddr + ChipCmd1) | Cmd1TxDemand,
>  		       ioaddr + ChipCmd1);
> -		IOSYNC;
> +		mmiowb();
>  	}
>  	else {
>  		/* This should never happen */
> 
> -- 
> Mathematics is the supreme nostalgia of our time.

-- 
Mathematics is the supreme nostalgia of our time.
-
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