[PATCH] Input: atkbd - Use ab83 as id when skipping the getid command

[PATCH] Input: atkbd - Use ab83 as id when skipping the getid command

[Hans de Goede]

Barnabás reported that the change to skip the getid command
when the controller is in translated mode on laptops caused
the Version field of his "AT Translated Set 2 keyboard"
input device to change from ab83 to abba, breaking a custom
hwdb entry for this keyboard.

Use the standard ab83 id for keyboards when getid is skipped
(rather then that getid fails) to avoid reporting a different
Version to userspace then before skipping the getid.

Fixes: 936e4d49ecbc ("Input: atkbd - skip ATKBD_CMD_GETID in translated mode")
Reported-by: Barnabás Pőcze <pobrn@protonmail.com>
Closes: https://lore.kernel.org/linux-input/W1ydwoG2fYv85Z3C3yfDOJcVpilEvGge6UGa9kZh8zI2-qkHXp7WLnl2hSkFz63j-c7WupUWI5TLL6n7Lt8DjRuU-yJBwLYWrreb1hbnd6A=@protonmail.com/
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/input/keyboard/atkbd.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/input/keyboard/atkbd.c b/drivers/input/keyboard/atkbd.c
index 786f00f6b7fd..13ef6284223d 100644
--- a/drivers/input/keyboard/atkbd.c
+++ b/drivers/input/keyboard/atkbd.c
@@ -791,9 +791,9 @@ static bool atkbd_is_portable_device(void)
  * not work. So in this case simply assume a keyboard is connected to avoid
  * confusing some laptop keyboards.
  *
- * Skipping ATKBD_CMD_GETID ends up using a fake keyboard id. Using a fake id is
- * ok in translated mode, only atkbd_select_set() checks atkbd->id and in
- * translated mode that is a no-op.
+ * Skipping ATKBD_CMD_GETID ends up using a fake keyboard id. Using the standard
+ * 0xab83 id is ok in translated mode, only atkbd_select_set() checks atkbd->id
+ * and in translated mode that is a no-op.
  */
 static bool atkbd_skip_getid(struct atkbd *atkbd)
 {
@@ -811,6 +811,7 @@ static int atkbd_probe(struct atkbd *atkbd)
 {
 	struct ps2dev *ps2dev = &atkbd->ps2dev;
 	unsigned char param[2];
+	bool skip_getid;
 
 /*
  * Some systems, where the bit-twiddling when testing the io-lines of the
@@ -832,7 +833,8 @@ static int atkbd_probe(struct atkbd *atkbd)
  */
 
 	param[0] = param[1] = 0xa5;	/* initialize with invalid values */
-	if (atkbd_skip_getid(atkbd) || ps2_command(ps2dev, param, ATKBD_CMD_GETID)) {
+	skip_getid = atkbd_skip_getid(atkbd);
+	if (skip_getid || ps2_command(ps2dev, param, ATKBD_CMD_GETID)) {
 
 /*
  * If the get ID command was skipped or failed, we check if we can at least set
@@ -842,7 +844,7 @@ static int atkbd_probe(struct atkbd *atkbd)
 		param[0] = 0;
 		if (ps2_command(ps2dev, param, ATKBD_CMD_SETLEDS))
 			return -1;
-		atkbd->id = 0xabba;
+		atkbd->id = skip_getid ? 0xab83 : 0xabba;
 		return 0;
 	}
 
-- 
2.43.0

Re: [PATCH] Input: atkbd - Use ab83 as id when skipping the getid command

[Dmitry Torokhov]

On Tue, Jan 16, 2024 at 09:43:25PM +0100, Hans de Goede wrote:
> Barnabás reported that the change to skip the getid command
> when the controller is in translated mode on laptops caused
> the Version field of his "AT Translated Set 2 keyboard"
> input device to change from ab83 to abba, breaking a custom
> hwdb entry for this keyboard.
> 
> Use the standard ab83 id for keyboards when getid is skipped
> (rather then that getid fails) to avoid reporting a different
> Version to userspace then before skipping the getid.
> 
> Fixes: 936e4d49ecbc ("Input: atkbd - skip ATKBD_CMD_GETID in translated mode")
> Reported-by: Barnabás Pőcze <pobrn@protonmail.com>
> Closes: https://lore.kernel.org/linux-input/W1ydwoG2fYv85Z3C3yfDOJcVpilEvGge6UGa9kZh8zI2-qkHXp7WLnl2hSkFz63j-c7WupUWI5TLL6n7Lt8DjRuU-yJBwLYWrreb1hbnd6A=@protonmail.com/
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Applied, thank you.

-- 
Dmitry