On 1/15/2019 2:47 PM, Wolfram Sang wrote:
On Tue, Oct 30, 2018 at 02:09:11PM -0700, Jae Hyun Yoo wrote:
In multi-master environment, this driver's master cannot know
exactly when a peer master sends data to this driver's slave so a
case can be happened that this master tries to send data through
the master_xfer function but slave data from peer master is still
being processed by this driver. To prevent state corruption in the
case, this patch adds checking code if any slave operation is
ongoing and it waits up to the bus timeout duration before starting
a master_xfer operation.
To support this change, it introduces changes on i2c-core-base to
make that able to read the bus timeout and master transfer retries
count values from device tree properties.
Please review this patch set.
Marking this as "Changes requested". I think if the mutex approach
works, these patches become obsolete then.
Hi Wolfram,
Thanks for your touching base. I made and tested a new patch in my
local. Actually, I couldn't use a mutex because it should provide
locking between driver context and interrupt context. Instead, after
taking lots of experiments, I checked that idle waiting can be supported
by this H/W so I didn't need to use any locking method in the driver
code for multi-master handling. I'll submit a new patch tomorrow using a
different thread. Please drop this patch set.
Thanks,
Jae
