Input: atkbd - use ab83 as id when skipping the getid command

commit 58f65f9db7e0de366a5a115c2e2c0703858bba69 upstream.

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>
Link: https://lore.kernel.org/r/20240116204325.7719-1-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/input/keyboard/atkbd.c b/drivers/input/keyboard/atkbd.c
index 786f00f..13ef628 100644 (file)
--- 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;
        }