On 2024/8/26 20:23, Zijun Hu wrote:

From: Zijun Hu quic_zijuhu@quicinc.com

drivers_probe_store() regards bus_rescan_devices_helper()'s returned value 0 as success when find driver for a single device user specify that is wrong since the following 3 failed cases also return 0:

(1) the device is dead (2) bus fails to match() the device with any its driver (3) bus fails to probe() the device with any its driver

Fixed by only regarding successfully attaching the device to a driver as success.

Fixes: b8c5cec23d5c ("Driver core: udev triggered device-<>driver binding") Cc: stable@vger.kernel.org Signed-off-by: Zijun Hu quic_zijuhu@quicinc.com

---

drivers/base/bus.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c index abf090ace833..0a994e63785c 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -40,6 +40,20 @@ static struct kset *bus_kset; struct driver_attribute driver_attr_##_name = \ __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) +/* Bus rescans drivers for a single device */ +static int __must_check bus_rescan_single_device(struct device *dev) +{

• int ret;
• if (dev->parent && dev->bus->need_parent_lock)

• device_lock(dev->parent);
  

• ret = device_attach(dev);
• if (dev->parent && dev->bus->need_parent_lock)

• device_unlock(dev->parent);
  

• return ret;

+}

static int __must_check bus_rescan_devices_helper(struct device *dev, void *data); @@ -311,12 +325,19 @@ static ssize_t drivers_probe_store(const struct bus_type *bus, { struct device *dev; int err = -EINVAL;

• int res;

dev = bus_find_device_by_name(bus, NULL, buf); if (!dev) return -ENODEV;

• if (bus_rescan_devices_helper(dev, NULL) == 0)

• res = bus_rescan_single_device(dev);
• /* Propagate error code upwards as far as possible */
• if (res < 0)

• err = res;
  

• else if (res == 1) err = count;
• put_device(dev); return err;

}

please ignore RFC for this patch, will push it within a patch series.

thanks

---

base-commit: 888f67e621dda5c2804a696524e28d0ca4cf0a80 change-id: 20240826-fix_drivers_probe-88c6a2cc1899

Best regards,