The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 25e9fbf0fd38868a429feabc38abebfc6dbf6542 Mon Sep 17 00:00:00 2001 From: "Isaac J. Manjarres" isaacmanjarres@google.com Date: Wed, 17 Aug 2022 11:40:26 -0700 Subject: [PATCH] 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
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index a8916d1bfdcb..ec69b43f926a 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -911,6 +911,11 @@ 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; @@ -1150,6 +1155,11 @@ 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;