On Fri, May 30, 2025 at 1:53 AM Armin Wolf <W_Armin@xxxxxx> wrote:
>
> On the MSI Modern 14 C5M the ECDT table contains invalid data:
>
> UID : 00000000
> GPE Number : 00 /* Invalid, 03 would be correct */
> Namepath : "" /* Invalid, "\_SB.PCI0.SBRG.EC" would
> * be correct
> */
>
> This slows down the EC access as the wrong GPE event is used for
> communication. Additionally the ID string is invalid.
>
> Ignore such faulty ECDT tables by verifying that the ID string has
> a valid format.
>
> Tested-by: glpnk@xxxxxxxxx
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
> drivers/acpi/ec.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
> index 6f4203716b53..75c7db8b156a 100644
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -23,8 +23,10 @@
> #include <linux/delay.h>
> #include <linux/interrupt.h>
> #include <linux/list.h>
> +#include <linux/printk.h>
> #include <linux/spinlock.h>
> #include <linux/slab.h>
> +#include <linux/string.h>
> #include <linux/suspend.h>
> #include <linux/acpi.h>
> #include <linux/dmi.h>
> @@ -2031,6 +2033,21 @@ void __init acpi_ec_ecdt_probe(void)
> goto out;
> }
>
> + if (!strstarts(ecdt_ptr->id, "\\")) {
> + /*
> + * The ECDT table on some MSI notebooks contains invalid data, together
> + * with an empty ID string ("").
> + *
> + * Section 5.2.15 of the ACPI specification requires the ID string to be
> + * 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.
> + */
> + pr_err(FW_BUG "Ignoring ECDT due to invalid ID string \"%s\"\n", ecdt_ptr->id);
> + goto out;
> + }
> +
> ec = acpi_ec_alloc();
> if (!ec)
> goto out;
> --
Applied as 6.16-rc material, thanks!
