On Fri, 25 Jul 2014 19:57:46 +0800, Jisheng Zhang wrote: > pca954x may be power lost during suspend, so after resume we also suffer > the issue fixed by commit cd823db8b1161ef0d756514d280715a576d65cc3, > > "pca954x power-on default is channel 0 connected. If multiple pca954x > muxes are connected to the same physical I2C bus, the parent bus will > see channel 0 devices behind both muxes by default." > > What's more, when resume bootloader may also operate the mux, so the > the channel connected after that may not be the one driver thought. > > We fix this problem by putting the mux to disconnected state and > clearing last_chan in the resume hook. > > Signed-off-by: Jisheng Zhang <[email protected]> > --- > drivers/i2c/muxes/i2c-mux-pca954x.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c > b/drivers/i2c/muxes/i2c-mux-pca954x.c > index 9bd4212..ec11b40 100644 > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > @@ -41,6 +41,7 @@ > #include <linux/i2c-mux.h> > #include <linux/i2c/pca954x.h> > #include <linux/module.h> > +#include <linux/pm.h> > #include <linux/slab.h> > > #define PCA954X_MAX_NCHANS 8 > @@ -273,9 +274,23 @@ static int pca954x_remove(struct i2c_client *client) > return 0; > } > > +#ifdef CONFIG_PM_SLEEP > +static int pca954x_resume(struct device *dev) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct pca954x *data = i2c_get_clientdata(client); > + > + data->last_chan = 0; > + return i2c_smbus_write_byte(client, 0); > +} > +#endif > + > +static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume); > + > static struct i2c_driver pca954x_driver = { > .driver = { > .name = "pca954x", > + .pm = &pca954x_pm, > .owner = THIS_MODULE, > }, > .probe = pca954x_probe,
Reviewed-by: Jean Delvare <[email protected]> -- Jean Delvare SUSE L3 Support -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
