[PATCH v3 1/4] HID: generic: Respect specialized drivers match callbacks

[Vas Zayarskiy]

A driver can reject an interface in its match callback even when its ID
table matches. hid-generic currently yields based on the ID table alone,
leaving such an interface without a driver.

Consult the callback after matching the ID table so hid-generic can keep
interfaces declined by specialized drivers. This allows the AMPINEL
hwmon driver to leave the separate keyboard interface to hid-generic.

The same callback check was proposed previously for Logitech devices:

Link: https://lkml.iu.edu/hypermail/linux/kernel/2212.0/06724.html

Assisted-by: LLM sparse
Signed-off-by: Vas Zayarskiy <contact@xxxxxxxxx>
---
 drivers/hid/hid-generic.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c
index c2de91674..ebc38ae76 100644
--- a/drivers/hid/hid-generic.c
+++ b/drivers/hid/hid-generic.c
@@ -31,7 +31,13 @@ static int __check_hid_generic(struct device_driver *drv, void *data)
 	if (hdrv == &hid_generic)
 		return 0;
 
-	return hid_match_device(hdev, hdrv) != NULL;
+	if (!hid_match_device(hdev, hdrv))
+		return 0;
+
+	if (hdrv->match)
+		return hdrv->match(hdev, false);
+
+	return 1;
 }
 
 static bool hid_generic_match(struct hid_device *hdev,