Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.
If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.
If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.
Cc: [email protected]
Cc: Saravana Kannan <[email protected]>
Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Reported-by: Guenter Roeck <[email protected]>
Signed-off-by: Isaac J. Manjarres <[email protected]>
Tested-by: Guenter Roeck <[email protected]>
Reviewed-by: Saravana Kannan <[email protected]>
---
drivers/base/dd.c | 10 ++++++++++
1 file changed, 10 insertions(+)
v1 -> v2:
- Fixed the logic in __driver_attach() to allow a driver to continue
attempting to match and bind with devices in case of any error, not
just probe deferral.
v2 -> v3:
- Restored the patch back to v1.
- Added Guenter's Tested-by tag.
- Added Saravana's Reviewed-by tag.
- Cc'd [email protected]
Greg,
This is the final version of this patch. Can you please pick this up?
Thanks,
Isaac
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 70f79fc71539..90b31fb141a5 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -881,6 +881,11 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
dev_dbg(dev, "Device match requests probe deferral\n");
dev->can_match = true;
driver_deferred_probe_add(dev);
+ /*
+ * Device can't match with a driver right now, so don't attempt
+ * to match or bind with other drivers on the bus.
+ */
+ return ret;
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
return ret;
@@ -1120,6 +1125,11 @@ static int __driver_attach(struct device *dev, void *data)
dev_dbg(dev, "Device match requests probe deferral\n");
dev->can_match = true;
driver_deferred_probe_add(dev);
+ /*
+ * Driver could not match with device, but may match with
+ * another device on the bus.
+ */
+ return 0;
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
return ret;
--
2.37.1.595.g718a3a8f04-goog
On Wed, Aug 17, 2022 at 11:40 AM Isaac J. Manjarres
<[email protected]> wrote:
>
> Both __device_attach_driver() and __driver_attach() check the return
> code of the bus_type.match() function to see if the device needs to be
> added to the deferred probe list. After adding the device to the list,
> the logic attempts to bind the device to the driver anyway, as if the
> device had matched with the driver, which is not correct.
>
> If __device_attach_driver() detects that the device in question is not
> ready to match with a driver on the bus, then it doesn't make sense for
> the device to attempt to bind with the current driver or continue
> attempting to match with any of the other drivers on the bus. So, update
> the logic in __device_attach_driver() to reflect this.
>
> If __driver_attach() detects that a driver tried to match with a device
> that is not ready to match yet, then the driver should not attempt to bind
> with the device. However, the driver can still attempt to match and bind
> with other devices on the bus, as drivers can be bound to multiple
> devices. So, update the logic in __driver_attach() to reflect this.
>
> Cc: [email protected]
> Cc: Saravana Kannan <[email protected]>
> Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
> Reported-by: Guenter Roeck <[email protected]>
> Signed-off-by: Isaac J. Manjarres <[email protected]>
> Tested-by: Guenter Roeck <[email protected]>
> Reviewed-by: Saravana Kannan <[email protected]>
> ---
> drivers/base/dd.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> v1 -> v2:
> - Fixed the logic in __driver_attach() to allow a driver to continue
> attempting to match and bind with devices in case of any error, not
> just probe deferral.
>
> v2 -> v3:
> - Restored the patch back to v1.
> - Added Guenter's Tested-by tag.
> - Added Saravana's Reviewed-by tag.
> - Cc'd [email protected]
>
> Greg,
>
> This is the final version of this patch. Can you please pick this up?
>
> Thanks,
> Isaac
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 70f79fc71539..90b31fb141a5 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -881,6 +881,11 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
> dev_dbg(dev, "Device match requests probe deferral\n");
> dev->can_match = true;
> driver_deferred_probe_add(dev);
> + /*
> + * Device can't match with a driver right now, so don't attempt
> + * to match or bind with other drivers on the bus.
> + */
> + return ret;
> } else if (ret < 0) {
> dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> return ret;
> @@ -1120,6 +1125,11 @@ static int __driver_attach(struct device *dev, void *data)
> dev_dbg(dev, "Device match requests probe deferral\n");
> dev->can_match = true;
> driver_deferred_probe_add(dev);
> + /*
> + * Driver could not match with device, but may match with
> + * another device on the bus.
> + */
> + return 0;
> } else if (ret < 0) {
> dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> return ret;
> --
> 2.37.1.595.g718a3a8f04-goog
>
Greg,
Can you pull this in for 6.0-rcX please? This is fixing a long
standing bug that was exposed by my amba code cleanup.
-Saravana
> Both __device_attach_driver() and __driver_attach() check the return
> code of the bus_type.match() function to see if the device needs to be
> added to the deferred probe list. After adding the device to the list,
> the logic attempts to bind the device to the driver anyway, as if the
> device had matched with the driver, which is not correct.
>
> If __device_attach_driver() detects that the device in question is not
> ready to match with a driver on the bus, then it doesn't make sense for
> the device to attempt to bind with the current driver or continue
> attempting to match with any of the other drivers on the bus. So, update
> the logic in __device_attach_driver() to reflect this.
>
> If __driver_attach() detects that a driver tried to match with a device
> that is not ready to match yet, then the driver should not attempt to bind
> with the device. However, the driver can still attempt to match and bind
> with other devices on the bus, as drivers can be bound to multiple
> devices. So, update the logic in __driver_attach() to reflect this.
>
> Cc: [email protected]
> Cc: Saravana Kannan <[email protected]>
> Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
> Reported-by: Guenter Roeck <[email protected]>
> Signed-off-by: Isaac J. Manjarres <[email protected]>
> Tested-by: Guenter Roeck <[email protected]>
> Reviewed-by: Saravana Kannan <[email protected]>
This fixes a QEMU regression for me:
Tested-by: Linus Walleij <[email protected]>
Yours,
Linus Walleij
Greg,
Are you happy for me to pick up this patch as part of the fixes for the
AMBA changes? The original patch that it is fixing is a patch that was
part of a series that was merged through my tree.
It's fixing a problem that has been noticed by several people and the
fix is now a few weeks old.
Thanks.
On Wed, Aug 17, 2022 at 11:40:26AM -0700, Isaac J. Manjarres wrote:
> Both __device_attach_driver() and __driver_attach() check the return
> code of the bus_type.match() function to see if the device needs to be
> added to the deferred probe list. After adding the device to the list,
> the logic attempts to bind the device to the driver anyway, as if the
> device had matched with the driver, which is not correct.
>
> If __device_attach_driver() detects that the device in question is not
> ready to match with a driver on the bus, then it doesn't make sense for
> the device to attempt to bind with the current driver or continue
> attempting to match with any of the other drivers on the bus. So, update
> the logic in __device_attach_driver() to reflect this.
>
> If __driver_attach() detects that a driver tried to match with a device
> that is not ready to match yet, then the driver should not attempt to bind
> with the device. However, the driver can still attempt to match and bind
> with other devices on the bus, as drivers can be bound to multiple
> devices. So, update the logic in __driver_attach() to reflect this.
>
> Cc: [email protected]
> Cc: Saravana Kannan <[email protected]>
> Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
> Reported-by: Guenter Roeck <[email protected]>
> Signed-off-by: Isaac J. Manjarres <[email protected]>
> Tested-by: Guenter Roeck <[email protected]>
> Reviewed-by: Saravana Kannan <[email protected]>
> ---
> drivers/base/dd.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> v1 -> v2:
> - Fixed the logic in __driver_attach() to allow a driver to continue
> attempting to match and bind with devices in case of any error, not
> just probe deferral.
>
> v2 -> v3:
> - Restored the patch back to v1.
> - Added Guenter's Tested-by tag.
> - Added Saravana's Reviewed-by tag.
> - Cc'd [email protected]
>
> Greg,
>
> This is the final version of this patch. Can you please pick this up?
>
> Thanks,
> Isaac
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 70f79fc71539..90b31fb141a5 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -881,6 +881,11 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
> dev_dbg(dev, "Device match requests probe deferral\n");
> dev->can_match = true;
> driver_deferred_probe_add(dev);
> + /*
> + * Device can't match with a driver right now, so don't attempt
> + * to match or bind with other drivers on the bus.
> + */
> + return ret;
> } else if (ret < 0) {
> dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> return ret;
> @@ -1120,6 +1125,11 @@ static int __driver_attach(struct device *dev, void *data)
> dev_dbg(dev, "Device match requests probe deferral\n");
> dev->can_match = true;
> driver_deferred_probe_add(dev);
> + /*
> + * Driver could not match with device, but may match with
> + * another device on the bus.
> + */
> + return 0;
> } else if (ret < 0) {
> dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> return ret;
> --
> 2.37.1.595.g718a3a8f04-goog
>
>
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
On Wed, Aug 31, 2022 at 09:21:29PM +0100, Russell King (Oracle) wrote:
> Greg,
>
> Are you happy for me to pick up this patch as part of the fixes for the
> AMBA changes? The original patch that it is fixing is a patch that was
> part of a series that was merged through my tree.
>
> It's fixing a problem that has been noticed by several people and the
> fix is now a few weeks old.
Sorry, I'm behind in driver core stuff. I'll pick it up later today.
greg k-h
On Thu, Sep 01, 2022 at 07:28:59AM +0200, Greg Kroah-Hartman wrote:
> On Wed, Aug 31, 2022 at 09:21:29PM +0100, Russell King (Oracle) wrote:
> > Greg,
> >
> > Are you happy for me to pick up this patch as part of the fixes for the
> > AMBA changes? The original patch that it is fixing is a patch that was
> > part of a series that was merged through my tree.
> >
> > It's fixing a problem that has been noticed by several people and the
> > fix is now a few weeks old.
>
> Sorry, I'm behind in driver core stuff. I'll pick it up later today.
Now queued up, thanks.
greg k-h