[PATCH v3 1/4] i2c: tegra: implement slave mode

Wolfram Sang wsa at the-dreams.de
Fri Jul 24 03:52:51 PDT 2015

> At the begin of my work on this patchset I even denied clock disable call if
> slave is registered (to minimize code that can affect transfer).

I hacked something like this, but it seems it was not enough.

> If only slave mode is used, then this logic is not needed.

This is not sufficent. We shouldn't break being a master only because we
also listen to a slave address (as long as the HW supports that of

> tegra_i2c_init is called on probe and resume. Also it is called in case of
> xfer fail. If xfer is ok, then I think slave addr must be kept unchanged.

This is fragile. Try scanning the bus with i2cdetect and slave setup
will be gone.

> As far as I understand it is a loopback mode. Probably it will not work
> (Stephen Warren already mentioned this).

Just to make clear: I am not saying we should support talking to our own
slave address. But it should still be possible to communicate with other
remote devices on the bus.


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