From 9e9c64131f47b0016911b76cebfcda6b1bb3b7b7 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Mon, 25 Jan 2021 21:52:58 +0100 Subject: [PATCH] platform/x86: thinkpad_acpi: Don't register keyboard_lang unnecessarily All recent ThinkPad BIOS-es support the GSKL method used to query the keyboard-layout used by the ECFW for the SHIFT + other-key key-press emulation for special keys such as e.g. the '=', '(' and ')' keys above the numpad on 15" models. So just checking for the method is not a good indicator of the model supporting getting/setting the keyboard_lang. On models where this is not supported GSKL succeeds, but it returns METHOD_ERR in the returned integer to indicate that this is not supported on this model. Add a check for METHOD_ERR and return -ENODEV if it is set to avoid registering a non-working keyboard_lang sysfs-attr on models where this is not supported. Cc: Nitin Joshi Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20210125205258.135664-1-hdegoede@redhat.com --- drivers/platform/x86/thinkpad_acpi.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 81f8ad6bb688..4a1dba3099a6 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -10047,6 +10047,13 @@ static int get_keyboard_lang(int *output) if (!acpi_evalf(gskl_handle, &kbd_lang, NULL, "dd", 0x02000000)) return -EIO; + /* + * METHOD_ERR gets returned on devices where there are no special (e.g. '=', + * '(' and ')') keys which use layout dependent key-press emulation. + */ + if (kbd_lang & METHOD_ERR) + return -ENODEV; + *output = kbd_lang; return 0;