On 01/13/2017 11:26 AM, Ville Syrjälä wrote:
There is an HW semaphore for I2C access. It is implemented in
drivers/i2c/busses/i2c-designware-baytrail.c and another set from Hans
is adding support for Cherrytrail into it.
It also feels quite hand wavy since the punit could do whatever at
any time AFAIK. Eg. if there's some thermal event or something the
punit might kick into action. So trying to protect this from the OS
side might not be able to avoid these problems entirely. It feels like
there really should be some kind of shared hardware/firmware mutex
with the punit to arbitrate access to the i2c bus.
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