On 2025-07-29 09:20, Armin Wolf wrote:
> It turns out that the ECDT table inside the ThinkBook 14 G7 IML
> contains a valid EC description but an invalid ID string
> ("_SB.PC00.LPCB.EC0"). Ignoring this ECDT based on the invalid
> ID string prevents the kernel from detecting the built-in touchpad,
> so relax the sanity check of the ID string and only reject ECDTs
> with empty ID strings.
>
> Compile-tested only.
>
> Reported-by: Ilya K <me@xxxxxxxx>
> Fixes: 7a0d59f6a913 ("ACPI: EC: Ignore ECDT tables with an invalid ID string")
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
> drivers/acpi/ec.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
Thanks, this works!
Tested-by: Ilya K <me@xxxxxxxx>
> diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
> index 75c7db8b156a..7855bbf752b1 100644
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -2033,7 +2033,7 @@ void __init acpi_ec_ecdt_probe(void)
> goto out;
> }
>
> - if (!strstarts(ecdt_ptr->id, "\\")) {
> + if (!strlen(ecdt_ptr->id)) {
> /*
> * The ECDT table on some MSI notebooks contains invalid data, together
> * with an empty ID string ("").
> @@ -2042,9 +2042,13 @@ void __init acpi_ec_ecdt_probe(void)
> * a "fully qualified reference to the (...) embedded controller device",
> * so this string always has to start with a backslash.
> *
> - * By verifying this we can avoid such faulty ECDT tables in a safe way.
> + * However some ThinkBook machines have a ECDT table with a valid EC
> + * description but an invalid ID string ("_SB.PC00.LPCB.EC0").
> + *
> + * Because of this we only check if the ID string is empty in order to
> + * avoid the obvious cases.
> */
> - pr_err(FW_BUG "Ignoring ECDT due to invalid ID string \"%s\"\n", ecdt_ptr->id);
> + pr_err(FW_BUG "Ignoring ECDT due to empty ID string\n");
> goto out;
> }
>
Would it maybe make sense to also log a warning for the old case? Maybe a vendor will notice it and fix the firmware...
(yeah yeah fat chance)
