smsc911x.c driver and SMP (was Re: Kernel related (?) user space crash at ARM11 MPCore)

[bgat@billgatliff.com (Bill Gatliff)]

Catalin Marinas wrote:
> (sorry for the repost Antti, the message was sent to the old list and
> didn't like the "was:" stuff in the subject and the reply headers)
>
> On Thu, 2009-08-13 at 00:05 +0300, Antti P Miettinen wrote:
>   
>> BTW - the smsc911x does not work for me in the
>> recent kernels. I had to change back to smc911x. Otherwise my boot
>> from NFS root hangs pretty early. I think it used to be the other way
>> around in some kernel version.
>>     
>
> I added the commit below to my tree and the new driver now seems to work
> fine with ARM11MPCore systems:
>
> http://www.linux-arm.org/git?p=linux-2.6.git;a=commitdiff;h=246a6cc1f1fa52e96a08f327337c5616eb634825
>
> I'm waiting for the SMSC guys to look into this issue. It may just be
> that some of the read-after-write or read-after-read timing constraints
> are violated when more than one CPU tries to access the Ethernet chip.
>
>   

Why take the lock in smsc911x_tx_writefifo?  It looks like you take the 
same lock again in smsc911x_reg_write.


b.g.

-- 
Bill Gatliff
bgat at billgatliff.com