Re: [PATCH] smc91c92_cs : add a spinlock to avoid race condition

From: Vaishali Thakkar
Date: Fri Aug 19 2016 - 00:42:31 EST




On Friday 19 August 2016 09:37 AM, David Miller wrote:
> From: Pavel Andrianov <andrianov@xxxxxxxxx>
> Date: Tue, 16 Aug 2016 16:39:06 +0300
>
>> smc_reset may be executed in parallel with timer function media_check.
>> To avoid data race in smc_set_xcvr a spinlock was added.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Pavel Andrianov <andrianov@xxxxxxxxx>
>
> This is not sufficient.
>
> You have to block basically the entire function, because both
> smc_reset and media_check program the bank selection so could
> corrupt eachother's register accesses.

Hmm, but then there is a use of udelay as well. Would it be still
fine to acquire a spinlock on whole function?

>

--
Vaishali