2002-06-24 02:38:43

by Frank Davis

[permalink] [raw]
Subject: [PATCH] 2.5.24 : drivers/net/defxx.c

Hello all,
The following patch adds the check for 32-bit DMA mapping functionality
for the defxx driver. This is the first step to make this driver compliant
with Documentation/DMA-mapping.txt . Please review.
Regards,
Frank

--- drivers/net/defxx.c.old Sun May 26 14:37:25 2002
+++ drivers/net/defxx.c Sun Jun 23 22:18:39 2002
@@ -427,7 +427,10 @@
printk(version); /* we only display this string ONCE */
}
#endif
-
+ if(pci_set_dma_mask(pdev, 0xffffffff))
+ {
+ printk(KERN_WARNING "defxx : No suitable DMA available\n");
+ }
/*
* init_fddidev() allocates a device structure with private data, clears the device structure and private data,
* and calls fddi_setup() and register_netdev(). Not much left to do for us here.



2002-06-24 08:49:46

by Maciej W. Rozycki

[permalink] [raw]
Subject: Re: [PATCH] 2.5.24 : drivers/net/defxx.c

On Sun, 23 Jun 2002, Frank Davis wrote:

> The following patch adds the check for 32-bit DMA mapping functionality
> for the defxx driver. This is the first step to make this driver compliant
> with Documentation/DMA-mapping.txt . Please review.

It's possible DEFPA is not limited to 32-bit addressing. The board was
designed with Alpha in mind, so it's likely it can address more (and a
brief look at the driver reveals there is room for 48 bits of address in
descriptor entries).

Has anyone seen documentation for the board?

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: [email protected], PGP key available +

2002-06-24 09:12:00

by Zwane Mwaikambo

[permalink] [raw]
Subject: Re: [PATCH] 2.5.24 : drivers/net/defxx.c

On Sun, 23 Jun 2002, Frank Davis wrote:

> -
> + if(pci_set_dma_mask(pdev, 0xffffffff))
> + {
> + printk(KERN_WARNING "defxx : No suitable DMA available\n");
> + }

Minor nit,
CodingStyle prefers this style;

if (pci_set_dma_mask(pdev, 0xffffffff))
printk(KERN_WARNING "defxx : No suitable DMA available\n");

Thanks,
Zwane Mwaikambo

--
http://function.linuxpower.ca


2002-06-24 14:19:53

by Jeff Garzik

[permalink] [raw]
Subject: Re: [PATCH] 2.5.24 : drivers/net/defxx.c

Maciej W. Rozycki wrote:
> It's possible DEFPA is not limited to 32-bit addressing. The board was
> designed with Alpha in mind, so it's likely it can address more (and a
> brief look at the driver reveals there is room for 48 bits of address in
> descriptor entries).
>
> Has anyone seen documentation for the board?


Until we find the docs, I think the patch is fair...

Jeff



2002-06-24 15:13:56

by Frank Davis

[permalink] [raw]
Subject: Re: [PATCH] 2.5.24 : drivers/net/defxx.c

According to
http://www.compaq.com/products/quickspecs/10477_na/10477_na.HTML

it explictly states 32-bit DMA addressing. It doesn't state anything to
suggest 48-bit addressing, which I would think it would if it were possible.

Regards,
Frank

Jeff Garzik wrote:
> Maciej W. Rozycki wrote:
> > It's possible DEFPA is not limited to 32-bit addressing. The board was
> > designed with Alpha in mind, so it's likely it can address more (and a
> > brief look at the driver reveals there is room for 48 bits of address in
> > descriptor entries).
> >
> > Has anyone seen documentation for the board?
>
>
> Until we find the docs, I think the patch is fair...
>
> Jeff
>
>
>
>


2002-06-24 15:32:08

by Frank Davis

[permalink] [raw]
Subject: Re: [PATCH] 2.5.24 : drivers/net/defxx.c

Zwane,
I agree, although eventually I envision the code to look like...

if(pci_set_dma_mask(pdev, 0xffffffff))
{
printk(KERN_WARNING "defxx : No suitable DMA available\n");
// Add appropriate action, such as
// goto err_dma_exit;
// OR
return -ENOMEM;
}

Thats why I have the braces (multiple statements).

Regards,
Frank

> Zwane Mwaikambo wrote:
>
>> On Sun, 23 Jun 2002, Frank Davis wrote:
>>
>>
>>> -
>>> + if(pci_set_dma_mask(pdev, 0xffffffff))
>>> + {
>>> + printk(KERN_WARNING "defxx : No suitable DMA available\n");
>>> + }
>>
>>
>>
>> Minor nit,
>> CodingStyle prefers this style;
>>
>> if (pci_set_dma_mask(pdev, 0xffffffff))
>> printk(KERN_WARNING "defxx : No suitable DMA available\n");
>>
>> Thanks,
>> Zwane Mwaikambo
>>
>
>


2002-06-24 16:02:07

by Maciej W. Rozycki

[permalink] [raw]
Subject: Re: [PATCH] 2.5.24 : drivers/net/defxx.c

On Mon, 24 Jun 2002, Frank Davis wrote:

> According to
> http://www.compaq.com/products/quickspecs/10477_na/10477_na.HTML
>
> it explictly states 32-bit DMA addressing. It doesn't state anything to
> suggest 48-bit addressing, which I would think it would if it were possible.

The page seems to refer to 32-bit data tranfers only, which is what an
average customer is about to understand. They don't even claim Linux
support anymore, like Digital used to for the A and B versions.

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: [email protected], PGP key available +