Sorry for the late reaction, but...
On Mon, 09 Nov 2015 12:45:42 +0200, Andy Shevchenko wrote:
> On Sat, 2015-11-07 at 12:35 +0100, Christian Fetzer wrote:
> (...)
> > @@ -129,10 +133,12 @@ static const struct dmi_system_id
> > piix4_dmi_ibm[] = {
> > };
> >
> > /* SB800 globals */
> > +DEFINE_MUTEX(piix4_mutex_sb800);
>
> Same question as for patch 3.
Noooooo!
The mutex is needed to ensure that only one of the 4 multiplexed SMBus
ports is used at any given time. i2c_piix4_adapdata is per i2c_adapter,
so if you move the mutex there you get one mutex per SMBus port, which
completely voids the point of having a mutex. A per-port mutex doesn't
protect anything, all it does is serialize the access to THAT port, but
i2c-core already takes care of this (thankfully.)
So moving this mutex to i2c_piix4_adapdata introduced a serious bug in
the driver, which needs to be fixed ASAP.
--
Jean Delvare
SUSE L3 Support
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