On Sat, Dec 17, 2016 at 12:10:56PM +0000, Russell King wrote:
> smbus functions return -ve on error, 0 on success.  However,
> __i2c_transfer() have a different return signature - -ve on error, or
> number of buffers transferred (which may be zero or greater.)
> 
> The upshot of this is that the sense of the test is reversed when using
> the mux on a bus supporting the master_xfer method: we cache the value
> and never retry if we fail to transfer any buffers, but if we succeed,
> we clear the cached value.
> 
> Fix this by making pca954x_reg_write() return a negative error code for
> all failure cases.
> 
> Fixes: 463e8f845cbf ("i2c: mux: pca954x: retry updating the mux selection on failure")
> Acked-by: Peter Rosin <peda@axentia.se>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Applied to for-current, thanks!