G920 device only advertises REPORT_ID_HIDPP_LONG and REPORT_ID_HIDPP_VERY_LONG in its HID report descriptor, so querying for REPORT_ID_HIDPP_SHORT with optional=false will always fail and prevent G920 to be recognized as a valid HID++ device.
To fix this and improve some other aspects, modify hidpp_validate_device() as follows:
- Inline the code of hidpp_validate_report() to simplify distingushing between non-present and invalid report descriptors
- Drop the check for id >= HID_MAX_IDS || id < 0 since all of our IDs are static and known to satisfy that at compile time
- Change the algorithms to check all possible report types (including very long report) and deem the device as a valid HID++ device if it supports at least one
- Treat invalid report length as a hard stop for the validation algorithm, meaning that if any of the supported reports has invalid length we assume the worst and treat the device as a generic HID device.
- Fold initialization of hidpp->very_long_report_length into hidpp_validate_device() since it already fetches very long report length and validates its value
Fixes: fe3ee1ec007b ("HID: logitech-hidpp: allow non HID++ devices to be handled by this module") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204191 Reported-by: Sam Bazely sambazley@fastmail.com Signed-off-by: Andrey Smirnov andrew.smirnov@gmail.com Cc: Jiri Kosina jikos@kernel.org Cc: Benjamin Tissoires benjamin.tissoires@redhat.com Cc: Henrik Rydberg rydberg@bitmath.org Cc: Pierre-Loup A. Griffais pgriffais@valvesoftware.com Cc: Austin Palmer austinp@valvesoftware.com Cc: linux-input@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # 5.2+ --- drivers/hid/hid-logitech-hidpp.c | 54 ++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 24 deletions(-)
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 85911586b3b6..8c4be991f387 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -3498,34 +3498,45 @@ static int hidpp_get_report_length(struct hid_device *hdev, int id) return report->field[0]->report_count + 1; }
-static bool hidpp_validate_report(struct hid_device *hdev, int id, - int expected_length, bool optional) +static bool hidpp_validate_device(struct hid_device *hdev) { - int report_length; + struct hidpp_device *hidpp = hid_get_drvdata(hdev); + int id, report_length, supported_reports = 0; + + id = REPORT_ID_HIDPP_SHORT; + report_length = hidpp_get_report_length(hdev, id); + if (report_length) { + if (report_length < HIDPP_REPORT_SHORT_LENGTH) + goto bad_device;
- if (id >= HID_MAX_IDS || id < 0) { - hid_err(hdev, "invalid HID report id %u\n", id); - return false; + supported_reports++; }
+ id = REPORT_ID_HIDPP_LONG; report_length = hidpp_get_report_length(hdev, id); - if (!report_length) - return optional; + if (report_length) { + if (report_length < HIDPP_REPORT_LONG_LENGTH) + goto bad_device;
- if (report_length < expected_length) { - hid_warn(hdev, "not enough values in hidpp report %d\n", id); - return false; + supported_reports++; }
- return true; -} + id = REPORT_ID_HIDPP_VERY_LONG; + report_length = hidpp_get_report_length(hdev, id); + if (report_length) { + if (report_length > HIDPP_REPORT_LONG_LENGTH && + report_length < HIDPP_REPORT_VERY_LONG_MAX_LENGTH) + goto bad_device;
-static bool hidpp_validate_device(struct hid_device *hdev) -{ - return hidpp_validate_report(hdev, REPORT_ID_HIDPP_SHORT, - HIDPP_REPORT_SHORT_LENGTH, false) && - hidpp_validate_report(hdev, REPORT_ID_HIDPP_LONG, - HIDPP_REPORT_LONG_LENGTH, true); + supported_reports++; + hidpp->very_long_report_length = report_length; + } + + return supported_reports; + +bad_device: + hid_warn(hdev, "not enough values in hidpp report %d\n", id); + return false; }
static bool hidpp_application_equals(struct hid_device *hdev, @@ -3572,11 +3583,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) return hid_hw_start(hdev, HID_CONNECT_DEFAULT); }
- hidpp->very_long_report_length = - hidpp_get_report_length(hdev, REPORT_ID_HIDPP_VERY_LONG); - if (hidpp->very_long_report_length > HIDPP_REPORT_VERY_LONG_MAX_LENGTH) - hidpp->very_long_report_length = HIDPP_REPORT_VERY_LONG_MAX_LENGTH; - if (id->group == HID_GROUP_LOGITECH_DJ_DEVICE) hidpp->quirks |= HIDPP_QUIRK_UNIFYING;