[patch 12/13] pcnet32 79C975 fiber fix

[patch 12/13] pcnet32 79C975 fiber fix

[akpm]

From: "HARDY, Steven" <steven.hardy@astrium.eads.net>

I have found a bug in the pcnet32 driver (drivers/net/pcnet32.c) affecting
all ethernet cards based on the AMD79C975 chip, using the fiber interface.

It's a one line fix, where some config registers get corrupted during
initialisation (which stops the Fiber interface working with this chip)

This bug was introduced somewhere betweeen 2.4.17 and 2.6.x (noticed whilst
upgrading to 2.6), and it may affect other chips too.  I have checked all
versions up to 2.6.11-bk6 and they are all broken.

Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 25-akpm/drivers/net/pcnet32.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletion(-)

diff -puN drivers/net/pcnet32.c~pcnet32-bug-79c975-fiber-fix drivers/net/pcnet32.c
--- 25/drivers/net/pcnet32.c~pcnet32-bug-79c975-fiber-fix	Tue Mar 15 14:19:55 2005
+++ 25-akpm/drivers/net/pcnet32.c	Tue Mar 15 14:19:55 2005
@@ -1351,7 +1351,8 @@ pcnet32_probe1(unsigned long ioaddr, int
 	printk(KERN_INFO "%s: registered as %s\n", dev->name, lp->name);
     cards_found++;
 
-    a->write_bcr(ioaddr, 2, 0x1002);	/* enable LED writes */
+    /* enable LED writes */
+    a->write_bcr(ioaddr, 2, a->read_bcr(ioaddr, 2) | 0x1002);
 
     return 0;
 
_

Re: [patch 12/13] pcnet32 79C975 fiber fix

[Don Fry]

I had not seen this problem until now.  The patch looks ok and
probably should have been written that way initially.  I have been
able to do a quick touch test with a 970A, 971, 972, 973, 975, 976, and
978 (some on ia32 and others on ppc64) without any adverse effects.
The 975 I have is copper not fiber.

Since only bit 12 is needed to enable LED writes, the code could
really be "a->write_bcr(ioaddr, 2, a->read_bcr(ioaddr, 2) | 0x1000);"
During pcnet32_open the ASEL bit is changed anyway.

This change should also be applied to 2.4.30 as well.


On Tue, Mar 15, 2005 at 02:22:48PM -0800, akpm@osdl.org wrote:
> 
> From: "HARDY, Steven" <steven.hardy@astrium.eads.net>
> 
> I have found a bug in the pcnet32 driver (drivers/net/pcnet32.c) affecting
> all ethernet cards based on the AMD79C975 chip, using the fiber interface.
> 
> It's a one line fix, where some config registers get corrupted during
> initialisation (which stops the Fiber interface working with this chip)
> 
> This bug was introduced somewhere betweeen 2.4.17 and 2.6.x (noticed whilst
> upgrading to 2.6), and it may affect other chips too.  I have checked all
> versions up to 2.6.11-bk6 and they are all broken.
> 
> Signed-off-by: Andrew Morton <akpm@osdl.org>
> ---
> 
>  25-akpm/drivers/net/pcnet32.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff -puN drivers/net/pcnet32.c~pcnet32-bug-79c975-fiber-fix drivers/net/pcnet32.c
> --- 25/drivers/net/pcnet32.c~pcnet32-bug-79c975-fiber-fix	Tue Mar 15 14:19:55 2005
> +++ 25-akpm/drivers/net/pcnet32.c	Tue Mar 15 14:19:55 2005
> @@ -1351,7 +1351,8 @@ pcnet32_probe1(unsigned long ioaddr, int
>  	printk(KERN_INFO "%s: registered as %s\n", dev->name, lp->name);
>      cards_found++;
>  
> -    a->write_bcr(ioaddr, 2, 0x1002);	/* enable LED writes */
> +    /* enable LED writes */
> +    a->write_bcr(ioaddr, 2, a->read_bcr(ioaddr, 2) | 0x1002);
>  
>      return 0;
>  
> _
> 
-- 
Don Fry
brazilnut@us.ibm.com

Re: [patch 12/13] pcnet32 79C975 fiber fix

[Andrew Morton]

Don Fry <brazilnut@us.ibm.com> wrote:
>
> I had not seen this problem until now.  The patch looks ok and
>  probably should have been written that way initially.  I have been
>  able to do a quick touch test with a 970A, 971, 972, 973, 975, 976, and
>  978 (some on ia32 and others on ppc64) without any adverse effects.
>  The 975 I have is copper not fiber.

Great, thanks.

>  Since only bit 12 is needed to enable LED writes, the code could
>  really be "a->write_bcr(ioaddr, 2, a->read_bcr(ioaddr, 2) | 0x1000);"
>  During pcnet32_open the ASEL bit is changed anyway.

OK, could you please prepare a final patch sometime and get it into Jeff? 
cc me as well please so I can update the patch I have.

>  This change should also be applied to 2.4.30 as well.

And that too, I guess.

Re: [patch 12/13] pcnet32 79C975 fiber fix

[Jeff Garzik]

Andrew Morton wrote:
> Don Fry <brazilnut@us.ibm.com> wrote:
> 
>>I had not seen this problem until now.  The patch looks ok and
>> probably should have been written that way initially.  I have been
>> able to do a quick touch test with a 970A, 971, 972, 973, 975, 976, and
>> 978 (some on ia32 and others on ppc64) without any adverse effects.
>> The 975 I have is copper not fiber.
> 
> 
> Great, thanks.
> 
> 
>> Since only bit 12 is needed to enable LED writes, the code could
>> really be "a->write_bcr(ioaddr, 2, a->read_bcr(ioaddr, 2) | 0x1000);"
>> During pcnet32_open the ASEL bit is changed anyway.
> 
> 
> OK, could you please prepare a final patch sometime and get it into Jeff? 
> cc me as well please so I can update the patch I have.

Yes, please do Don, if you have the time.

	Jeff