On Mon, 27 Feb 2012 23:52:23 +0100, Daniel Vetter wrote: > On Mon, Feb 27, 2012 at 11:20:40PM +0100, Jean Delvare wrote: > > If you need to hot-switch between hardware and bit-banged I2C, I suggest > > that you lock the bus while doing so, to avoid switching while a > > transaction is in progress. This can be achieved with > > i2c_lock_adapter() and i2c_unlock_adapter(). > > The drm/i915 xfer function is currently protected by a single mutex > (because the hw i2c controller can only be used on one bus at a time). So > I think we're covered. Also we do the fallback in our xfer function when > we notice that things don't quite work as they should, so we actually want > to switch while a transfer is in progress. Dunno whether that's the best > approach, but the current code is structured like this. This seems perfectly sane. > (...) > I've noticed that the the bit-banging algo does some test upon > registration but figured that it's not worth the fuss to add a new init > function that avoids the registration. Note that thanks to the way things are implemented in i2c-algo-bit, you'd really only have to write a new wrapper around __i2c_bit_add_bus(), so this is really only 1 line of code. That being said, I am not insisting, it's really up to you. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
