[Intel-gfx] [PATCH 1/7] x86/platform/intel/iosf_mbi: Add a mutex for punit access

[Andy Shevchenko]

On Sun, 2017-01-08 at 16:30 +0100, Hans de Goede wrote:
> Hi,
> 
> On 08-01-17 16:16, Andy Shevchenko wrote:
> > On Sun, 2017-01-08 at 14:44 +0100, Hans de Goede wrote:
> > > One some systems the punit accesses the pmic to change various
> > > voltages
> > > through the same bus as other kernel drivers use for e.g. battery
> > > monitoring.
> > > 
> > > If a driver sends requests to the punit which require the punit to
> > > access
> > > the pmic bus while another driver is also accessing the pmic bus
> > > various
> > > bad things happen.
> > > 
> > > This commit adds a mutex to protect the punit against simultaneous
> > > accesses
> > > and 2 functions to lock / unlock this mutex.
> > > 
> > > Note on these systems the i2c-bus driver will request a sempahore
> > > from
> > > the
> > > punit for exclusive access to the pmic bus when i2c drivers are
> > > accessing
> > > it, but this does not appear to be sufficient, we still need to
> > > avoid
> > > making certain punit requests during the access window to avoid
> > > problems.
> > 
> > I'm fine with the patch, but please spell
> > P-Unit
> > PMIC
> 
> In the commit msg and comments, not in code you mean I assume ?

Correct.

-- 
Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Intel Finland Oy