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-rw-r--r--drivers/acpi/ec.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 9d66a47d32fb..49e16f009095 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -194,6 +194,7 @@ static struct workqueue_struct *ec_query_wq;
static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
+static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
/* --------------------------------------------------------------------------
* Logging/Debugging
@@ -499,6 +500,26 @@ static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
ec_log_drv("event blocked");
}
+/*
+ * Process _Q events that might have accumulated in the EC.
+ * Run with locked ec mutex.
+ */
+static void acpi_ec_clear(struct acpi_ec *ec)
+{
+ int i, status;
+ u8 value = 0;
+
+ for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
+ status = acpi_ec_query(ec, &value);
+ if (status || !value)
+ break;
+ }
+ if (unlikely(i == ACPI_EC_CLEAR_MAX))
+ pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
+ else
+ pr_info("%d stale EC events cleared\n", i);
+}
+
static void acpi_ec_enable_event(struct acpi_ec *ec)
{
unsigned long flags;
@@ -507,6 +528,10 @@ static void acpi_ec_enable_event(struct acpi_ec *ec)
if (acpi_ec_started(ec))
__acpi_ec_enable_event(ec);
spin_unlock_irqrestore(&ec->lock, flags);
+
+ /* Drain additional events if hardware requires that */
+ if (EC_FLAGS_CLEAR_ON_RESUME)
+ acpi_ec_clear(ec);
}
#ifdef CONFIG_PM_SLEEP
@@ -1821,6 +1846,31 @@ static int ec_flag_query_handshake(const struct dmi_system_id *id)
#endif
/*
+ * On some hardware it is necessary to clear events accumulated by the EC during
+ * sleep. These ECs stop reporting GPEs until they are manually polled, if too
+ * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
+ *
+ * https://bugzilla.kernel.org/show_bug.cgi?id=44161
+ *
+ * Ideally, the EC should also be instructed NOT to accumulate events during
+ * sleep (which Windows seems to do somehow), but the interface to control this
+ * behaviour is not known at this time.
+ *
+ * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
+ * however it is very likely that other Samsung models are affected.
+ *
+ * On systems which don't accumulate _Q events during sleep, this extra check
+ * should be harmless.
+ */
+static int ec_clear_on_resume(const struct dmi_system_id *id)
+{
+ pr_debug("Detected system needing EC poll on resume.\n");
+ EC_FLAGS_CLEAR_ON_RESUME = 1;
+ ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
+ return 0;
+}
+
+/*
* Some ECDTs contain wrong register addresses.
* MSI MS-171F
* https://bugzilla.kernel.org/show_bug.cgi?id=12461
@@ -1869,6 +1919,9 @@ static const struct dmi_system_id ec_dmi_table[] __initconst = {
ec_honor_ecdt_gpe, "ASUS X580VD", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
+ {
+ ec_clear_on_resume, "Samsung hardware", {
+ DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
{},
};