[PATCH resend 0/1] HID: apple: Disable Fn-key key-re-mapping on clone keyboards

[PATCH resend 0/1] HID: apple: Disable Fn-key key-re-mapping on clone keyboards

[Hans de Goede]

Hi,

This one seems to have fallen through the cracks, hence this resend.

Regards,

Hans

[PATCH resend] HID: apple: Disable Fn-key key-re-mapping on clone keyboards

[Hans de Goede]

The Maxxter KB-BT-001 Bluetooth keyboard, which looks somewhat like the
Apple Wireless Keyboard, is using the vendor and product IDs (05AC:0239)
of the Apple Wireless Keyboard (2009 ANSI version) <sigh>.

But its F1 - F10 keys are marked as sending F1 - F10, not the special
functions hid-apple.c maps them too; and since its descriptors do not
contain the HID_UP_CUSTOM | 0x0003 usage apple-hid looks for for the
Fn-key, apple_setup_input() never gets called, so F1 - F6 are mapped
to key-codes which have not been set in the keybit array causing them
to not send any events at all.

The lack of a usage code matching the Fn key in the clone is actually
useful as this allows solving this problem in a generic way.

This commits adds a fn_found flag and it adds a input_configured
callback which checks if this flag is set once all usages have been
mapped. If it is not set, then assume this is a clone and clear the
quirks bitmap so that the hid-apple code does not add any special
handling to this keyboard.

This fixes F1 - F6 not sending anything at all and F7 - F12 sending
the wrong codes on the Maxxter KB-BT-001 Bluetooth keyboard and on
similar clones.

Cc: Joao Moreno <mail@joaomoreno.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Note hid-apple also enables APPLE_NUMLOCK_EMULATION for
USB_DEVICE_ID_APPLE_ALU_WIRELESS_2009_ANSI. At least on the Maxxter clone
this causes numlock to get stuck in the pressed state after pressing it
twice (its get stuck when pressed when the numlock led is on). This might
be specific to the clone, but it would be good to also check if this is
not an issue on an actual Apple Wireless Keyboard.

Joao, can you check the numlock-emulation stuff on your 05AC:0256
(APPLE_ALU_WIRELESS_2011_ISO) keyboard?
---
 drivers/hid/hid-apple.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
index 359bdfbe3701..e82f604d33e9 100644
--- a/drivers/hid/hid-apple.c
+++ b/drivers/hid/hid-apple.c
@@ -60,6 +60,7 @@ MODULE_PARM_DESC(swap_fn_leftctrl, "Swap the Fn and left Control keys. "
 struct apple_sc {
 	unsigned long quirks;
 	unsigned int fn_on;
+	unsigned int fn_found;
 	DECLARE_BITMAP(pressed_numlock, KEY_CNT);
 };
 
@@ -365,12 +366,15 @@ static int apple_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
 {
+	struct apple_sc *asc = hid_get_drvdata(hdev);
+
 	if (usage->hid == (HID_UP_CUSTOM | 0x0003) ||
 			usage->hid == (HID_UP_MSVENDOR | 0x0003) ||
 			usage->hid == (HID_UP_HPVENDOR2 | 0x0003)) {
 		/* The fn key on Apple USB keyboards */
 		set_bit(EV_REP, hi->input->evbit);
 		hid_map_usage_clear(hi, usage, bit, max, EV_KEY, KEY_FN);
+		asc->fn_found = true;
 		apple_setup_input(hi->input);
 		return 1;
 	}
@@ -397,6 +401,19 @@ static int apple_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 	return 0;
 }
 
+static int apple_input_configured(struct hid_device *hdev,
+		struct hid_input *hidinput)
+{
+	struct apple_sc *asc = hid_get_drvdata(hdev);
+
+	if ((asc->quirks & APPLE_HAS_FN) && !asc->fn_found) {
+		hid_info(hdev, "Fn key not found (Apple Wireless Keyboard clone?), disabling Fn key handling\n");
+		asc->quirks = 0;
+	}
+
+	return 0;
+}
+
 static int apple_probe(struct hid_device *hdev,
 		const struct hid_device_id *id)
 {
@@ -611,6 +628,7 @@ static struct hid_driver apple_driver = {
 	.event = apple_event,
 	.input_mapping = apple_input_mapping,
 	.input_mapped = apple_input_mapped,
+	.input_configured = apple_input_configured,
 };
 module_hid_driver(apple_driver);
 
-- 
2.26.2

Re: [PATCH resend] HID: apple: Disable Fn-key key-re-mapping on clone keyboards

[Jiri Kosina]

On Sat, 20 Jun 2020, Hans de Goede wrote:

> The Maxxter KB-BT-001 Bluetooth keyboard, which looks somewhat like the
> Apple Wireless Keyboard, is using the vendor and product IDs (05AC:0239)
> of the Apple Wireless Keyboard (2009 ANSI version) <sigh>.

Oh my god *smacks forehead*.

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs