driver core: Don't probe devices after bus_type.match() probe deferral
authorIsaac J. Manjarres <isaacmanjarres@google.com>
Wed, 17 Aug 2022 18:40:26 +0000 (11:40 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 1 Sep 2022 13:57:13 +0000 (15:57 +0200)
commit25e9fbf0fd38868a429feabc38abebfc6dbf6542
treeb17926aa5b3da337c95906cb49f6e595c2c47c2d
parenta4f124908617553ea3929a17293cea4960c92ba3
driver core: Don't probe devices after bus_type.match() probe deferral

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.

Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan <saravanak@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/base/dd.c