[PATCH] 2.5.24 : drivers/net/defxx.c

[PATCH] 2.5.24 : drivers/net/defxx.c

[Frank Davis]

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.

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

[Zwane Mwaikambo]

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
		

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

[Maciej W. Rozycki]

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: macro@ds2.pg.gda.pl, PGP key available        +

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

[Jeff Garzik]

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

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

[Frank Davis]

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
> 
> 
> 
> 

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

[Frank Davis]

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
>>
> 
> 

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

[Maciej W. Rozycki]

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: macro@ds2.pg.gda.pl, PGP key available        +