[PATCH] w1: Fix slave count on 1-Wire bus (resend)

[PATCH] w1: Fix slave count on 1-Wire bus (resend)

[Alex A. Mihaylov]

1-Wire bus have very fast algorith for exchange with single slave
device. Fix incorrect count of slave devices on connect second slave
device. This case on slave device probe() step we need use generic
(multislave) functions for read/write device.

Signed-off-by: Alex A. Mihaylov <minimumlaw@rambler.ru>
---
 drivers/w1/w1.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 90a3d93..5b8b976 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -731,6 +731,7 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 	atomic_set(&sl->refcnt, 1);
 	atomic_inc(&sl->master->refcnt);
+	dev->slave_count++;
 
 	/* slave modules need to be loaded in a context with unlocked mutex */
 	mutex_unlock(&dev->mutex);
@@ -750,11 +751,11 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 
 	sl->family = f;
 
-
 	err = __w1_attach_slave_device(sl);
 	if (err < 0) {
 		dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 			 sl->name);
+		dev->slave_count--;
 		w1_family_put(sl->family);
 		atomic_dec(&sl->master->refcnt);
 		kfree(sl);
@@ -762,7 +763,6 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	}
 
 	sl->ttl = dev->slave_ttl;
-	dev->slave_count++;
 
 	memcpy(msg.id.id, rn, sizeof(msg.id));
 	msg.type = W1_SLAVE_ADD;
-- 
2.8.4 (Apple Git-73)

Re: [PATCH] w1: Fix slave count on 1-Wire bus (resend)

[Greg Kroah-Hartman]

On Sat, Jun 10, 2017 at 10:43:36AM +0300, Evgeniy Polyakov wrote:
> Hi
> 
> 30.05.2017, 21:04, "Alex A. Mihaylov" <minimumlaw@rambler.ru>:
> > 1-Wire bus have very fast algorith for exchange with single slave
> > device. Fix incorrect count of slave devices on connect second slave
> > device. This case on slave device probe() step we need use generic
> > (multislave) functions for read/write device.
> >
> > Signed-off-by: Alex A. Mihaylov <minimumlaw@rambler.ru>
> 
> Thank you.
> 
> Greg, please pull this into your tree, it is a bugfix and probably should go quicker path
> 
> Acked-by: Evgeniy Polyakov <zbr@ioremap.net>

I can't find the original version of this.  Alex, can you please resend
it to me, with Evgeniy's ack on it?

thanks,

greg k-h

[PATCH] w1: Fix slave count on 1-Wire bus (resend)

[Alex A. Mihaylov]

1-Wire bus have very fast algorith for exchange with single slave
device. Fix incorrect count of slave devices on connect second slave
device. This case on slave device probe() step we need use generic
(multislave) functions for read/write device.

Signed-off-by: Alex A. Mihaylov <minimumlaw@rambler.ru>
---
 drivers/w1/w1.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 90a3d93..5b8b976 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -731,6 +731,7 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 	atomic_set(&sl->refcnt, 1);
 	atomic_inc(&sl->master->refcnt);
+	dev->slave_count++;
 
 	/* slave modules need to be loaded in a context with unlocked mutex */
 	mutex_unlock(&dev->mutex);
@@ -750,11 +751,11 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 
 	sl->family = f;
 
-
 	err = __w1_attach_slave_device(sl);
 	if (err < 0) {
 		dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 			 sl->name);
+		dev->slave_count--;
 		w1_family_put(sl->family);
 		atomic_dec(&sl->master->refcnt);
 		kfree(sl);
@@ -762,7 +763,6 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	}
 
 	sl->ttl = dev->slave_ttl;
-	dev->slave_count++;
 
 	memcpy(msg.id.id, rn, sizeof(msg.id));
 	msg.type = W1_SLAVE_ADD;
-- 
2.8.4 (Apple Git-73)