Re: oz6812, yenta_socket and madwifi

[Peter Staubach]

Daniel Ritz wrote:

> hi
>
> since i'm the one that put that code there in the first place i guess
> i have to comment on it :)
>
> the attached patch should also fix your problem. and it cleans up the
> magic numbers a bit.
>
> rgds
> -daniel
>
> -------------
>
> [PATCH] disable read prefetch/write burst on old O2Micro bridges
>
> older O2Micro bridges have problems with both read prefetch and write burst
> depending on the combination of the chipset, bridge, cardbus card. safest
> is to disable read prefetch and write burst on those old bridges.
>
> Signed-off-by: Daniel Ritz <daniel.ritz@xxxxxx>
>
> diff --git a/drivers/pcmcia/o2micro.h b/drivers/pcmcia/o2micro.h
> --- a/drivers/pcmcia/o2micro.h
> +++ b/drivers/pcmcia/o2micro.h
> @@ -120,11 +120,16 @@
> #define  O2_MODE_E_LED_OUT	0x08
> #define  O2_MODE_E_SKTA_ACTV	0x10
>
> +#define O2_RESERVED1		0x94
> +#define O2_RESERVED2		0xD4
> +#define O2_RES_READ_PREFETCH	0x02
> +#define O2_RES_WRITE_BURST	0x08
> +
> static int o2micro_override(struct yenta_socket *socket)
> {
> 	/*
> -	 * 'reserved' register at 0x94/D4. chaning it to 0xCA (8 bit) enables
> -	 * read prefetching which for example makes the RME Hammerfall DSP
> +	 * 'reserved' register at 0x94/D4. allows setting read prefetch and write
> +	 * bursting. read prefetching for example makes the RME Hammerfall DSP
> 	 * working. for some bridges it is at 0x94, for others at 0xD4. it's
> 	 * ok to write to both registers on all O2 bridges.
> 	 * from Eric Still, 02Micro.
> @@ -132,20 +137,35 @@ static int o2micro_override(struct yenta
> 	u8 a, b;
>
> 	if (PCI_FUNC(socket->dev->devfn) == 0) {
> -		a = config_readb(socket, 0x94);
> -		b = config_readb(socket, 0xD4);
> +		a = config_readb(socket, O2_RESERVED1);
> +		b = config_readb(socket, O2_RESERVED2);
>
> 		printk(KERN_INFO "Yenta O2: res at 0x94/0xD4: %02x/%02x\n", a, b);
>
> 		switch (socket->dev->device) {
> +		/*
> +		 * older bridges have problems with both read prefetch and write
> +		 * bursting depending on the combination of the chipset, bridge
> +		 * and the cardbus card. so disable them to be on the safe side.
> +		 */
> +		case PCI_DEVICE_ID_O2_6729:
> +		case PCI_DEVICE_ID_O2_6730:
> +		case PCI_DEVICE_ID_O2_6812:
> 		case PCI_DEVICE_ID_O2_6832:
> -			printk(KERN_INFO "Yenta O2: old bridge, not enabling read prefetch / write burst\n");
> +		case PCI_DEVICE_ID_O2_6836:
> +			printk(KERN_INFO "Yenta O2: old bridge, disabling read prefetch/write burst\n");
> +			config_writeb(socket, O2_RESERVED1,
> +			              a & ~(O2_RES_READ_PREFETCH | O2_RES_READ_PREFETCH));
> +			config_writeb(socket, O2_RESERVED2,
> +			              b & ~(O2_RES_READ_PREFETCH | O2_RES_READ_PREFETCH));
> 			break;
>
> 		default:
> 			printk(KERN_INFO "Yenta O2: enabling read prefetch/write burst\n");
> -			config_writeb(socket, 0x94, a | 0x0a);
> -			config_writeb(socket, 0xD4, b | 0x0a);
> +			config_writeb(socket, O2_RESERVED1,
> +			              a | O2_RES_READ_PREFETCH | O2_RES_READ_PREFETCH);
> +			config_writeb(socket, O2_RESERVED2,
> +			              b | O2_RES_READ_PREFETCH | O2_RES_READ_PREFETCH);
> 		}
> 	}

Shouldn't the two pairs of calls to config_writeb() be using
"O2_RES_READ_PREFETCH | O2_RES_WRITE_BURST" instead of
"O2_RES_READ_PREFETCH | O2_RES_READ_PREFETCH"?

   Thanx...

      ps
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/