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Vincent Liu ea34511aaf driver core: Check drivers_autoprobe for all added devices ...

When a device is hot-plugged, the drivers_autoprobe sysfs attribute is
not checked (at least for PCI devices). This means that
drivers_autoprobe is not working as intended, e.g. hot-plugged PCI
devices will still be autoprobed and bound to drivers even with
drivers_autoprobe disabled.

The problem likely started when device_add() was removed from
pci_bus_add_device() in commit 4f535093cf ("PCI: Put pci_dev in device
tree as early as possible") which means that the check for
drivers_autoprobe which used to happen in bus_probe_device() is no
longer present (previously bus_add_device() calls bus_probe_device()).
Conveniently, in commit 9170304169 ("PCI: Allow built-in drivers to
use async initial probing") device_attach() was replaced with
device_initial_probe() which faciliates this change to push the check
for drivers_autoprobe into device_initial_probe().

Make sure all devices check drivers_autoprobe by pushing the
drivers_autoprobe check into device_initial_probe(). This will only
affect devices on the PCI bus for now as device_initial_probe() is only
called by pci_bus_add_device() and bus_probe_device(), but
bus_probe_device() already checks for autoprobe, so callers of
bus_probe_device() should not observe changes on autoprobing.
Note also that pushing this check into device_initial_probe() rather
than device_attach() makes it only affect automatic probing of
drivers (e.g. when a device is hot-plugged), userspace can still choose
to manually bind a driver by writing to drivers_probe sysfs attribute,
even with autoprobe disabled.

Any future callers of device_initial_probe() will respect the
drivers_autoprobe sysfs attribute, which is the intended purpose of
drivers_autoprobe.

Signed-off-by: Vincent Liu <vincent.liu@nutanix.com>
Link: https://patch.msgid.link/20251022120740.2476482-1-vincent.liu@nutanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2025-11-26 15:22:19 +01:00

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