On Wed, Sep 14, 2011 at 01:45:47PM +0300, Antti Palosaari wrote: > >>Interesting idea, but it didn't worked. It deadlocks. I think it > >>locks since I2C-mux is controlled by I2C "switch" in same I2C bus, > >>not GPIO or some other HW. > > > >Take a look at drivers/i2c/muxes/pca954x.c. You need to use > >parent->algo->master_xfer/smbus_xfer directly as the lock that > >protects you from having both gates open is the lock of the > >root i2c bus. > > Ah yes, rather similar case. I see it as commented in pca954x.c: > /* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() > for this as they will try to lock adapter a second time */ > > This looks even more hackish solution than calling existing demod > .i2c_gate_ctrl() callback from USB-interface driver. But yes, it > must work - not beautiful but workable workaround. This is not a hack. This is the official way to do it. The I2C mux framework was designed to allow multiplexers controlled through the same I2C bus. Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
