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

From: Vaishali Thakkar <redacted>
Date: Fri, 19 Aug 2016 10:11:32 +0530

On Friday 19 August 2016 09:37 AM, David Miller wrote:

quoted

From: Pavel Andrianov <redacted>
Date: Tue, 16 Aug 2016 16:39:06 +0300

quoted

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 <redacted>

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?

I don't know, but what I'm telling you is that you have to execute
register programming these two functions do atomically so that the
bank selection doesn't check get changed midstream.