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The driver may want to communicate with the > > device as part of the driver remove operation, so the dev_num > > should remain assigned until that has completed. > > That change looks fine. > > Reviewed-by: Pierre-Louis Bossart > > But I am a bit worried about the dev_num handling now that I think of > it. This is *only* at the manager level. At the peripheral level, the > dev_num register has not been modified so the hardware still reports as > ATTACHED with the dev_num whose mask was cleared on the host side. > IOW we have a zombie peripheral on the link, and if we do a sequence > rmmod/insmod things could be fun... I think there is also a bit of a race here as well. I think we can't access slave after we call device_unregister. Will think about this a little more and prepare a v2. We can probably cache the dev_num before but can't help wondering if we are clearing the dev_num in the right place. Thanks, Charles > > Signed-off-by: Charles Keepax > > --- > > drivers/soundwire/bus.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c > > index aeaae5a57c89d..b17718f4277ed 100644 > > --- a/drivers/soundwire/bus.c > > +++ b/drivers/soundwire/bus.c > > @@ -175,8 +175,9 @@ static int sdw_delete_slave(struct device *dev, void *data) > > > > sdw_slave_debugfs_exit(slave); > > > > - mutex_lock(&bus->bus_lock); > > + device_unregister(dev); > > > > + mutex_lock(&bus->bus_lock); > > if (slave->dev_num) { /* clear dev_num if assigned */ > > clear_bit(slave->dev_num, bus->assigned); > > if (bus->ops && bus->ops->put_device_num) > > @@ -185,7 +186,6 @@ static int sdw_delete_slave(struct device *dev, void *data) > > list_del_init(&slave->node); > > mutex_unlock(&bus->bus_lock); > > > > - device_unregister(dev); > > return 0; > > } > > >