HID: add per device quirk to force bind to hid-generic

We already have the possibility to force not binding to hid-generic and
rely on a dedicated driver, but we couldn't do the other way around.

This is useful for BPF programs where we are fixing the report descriptor
and the events, but want to avoid a specialized driver to come after BPF
which would unwind everything that is done there.

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://patch.msgid.link/20241001-hid-bpf-hid-generic-v3-8-2ef1019468df@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 8e87993..f1c23b2 100644 (file)
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2698,9 +2698,10 @@ static bool hid_check_device_match(struct hid_device *hdev,
        /*
         * hid-generic implements .match(), so we must be dealing with a
         * different HID driver here, and can simply check if
-        * hid_ignore_special_drivers is set or not.
+        * hid_ignore_special_drivers or HID_QUIRK_IGNORE_SPECIAL_DRIVER
+        * are set or not.
         */
-       return !hid_ignore_special_drivers;
+       return !hid_ignore_special_drivers && !(hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER);
 }
 
 static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)

diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c
index f9db991..88882c1 100644 (file)
--- a/drivers/hid/hid-generic.c
+++ b/drivers/hid/hid-generic.c
@@ -40,6 +40,9 @@ static bool hid_generic_match(struct hid_device *hdev,
        if (ignore_special_driver)
                return true;
 
+       if (hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER)
+               return true;
+
        if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)
                return false;
 

diff --git a/include/linux/hid.h b/include/linux/hid.h
index ff58b5c..63330d6 100644 (file)
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -359,6 +359,7 @@ struct hid_item {
  * | @HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP:
  * | @HID_QUIRK_HAVE_SPECIAL_DRIVER:
  * | @HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE:
+ * | @HID_QUIRK_IGNORE_SPECIAL_DRIVER
  * | @HID_QUIRK_FULLSPEED_INTERVAL:
  * | @HID_QUIRK_NO_INIT_REPORTS:
  * | @HID_QUIRK_NO_IGNORE:
@@ -384,6 +385,7 @@ struct hid_item {
 #define HID_QUIRK_HAVE_SPECIAL_DRIVER          BIT(19)
 #define HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE BIT(20)
 #define HID_QUIRK_NOINVERT                     BIT(21)
+#define HID_QUIRK_IGNORE_SPECIAL_DRIVER                BIT(22)
 #define HID_QUIRK_FULLSPEED_INTERVAL           BIT(28)
 #define HID_QUIRK_NO_INIT_REPORTS              BIT(29)
 #define HID_QUIRK_NO_IGNORE                    BIT(30)