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authorArmin Wolf <W_Armin@gmx.de>2025-05-30 01:53:10 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2025-06-10 20:55:31 +0200
commit7a0d59f6a913a2bc7680c663b8cf1e45d1bdbf26 (patch)
treefb7914ccd89c7b39ccecff3c24264421bfbe27a2
parent19272b37aa4f83ca52bdf9c16d5d81bdd1354494 (diff)
ACPI: EC: Ignore ECDT tables with an invalid ID string
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@proton.me Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://patch.msgid.link/20250529235310.540530-1-W_Armin@gmx.de Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/acpi/ec.c17
1 files changed, 17 insertions, 0 deletions
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;