diff options
Diffstat (limited to 'drivers/acpi/ec.c')
| -rw-r--r-- | drivers/acpi/ec.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 959d41acc108..d7d32c28829b 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -67,6 +67,8 @@ enum ec_command { #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */ #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */ #define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */ +#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query + * when trying to clear the EC */ enum { EC_FLAGS_QUERY_PENDING, /* Query is pending */ @@ -116,6 +118,7 @@ EXPORT_SYMBOL(first_ec); static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */ static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */ static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */ +static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */ /* -------------------------------------------------------------------------- Transaction Management @@ -440,6 +443,29 @@ acpi_handle ec_get_handle(void) EXPORT_SYMBOL(ec_get_handle); +static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data); + +/* + * Clears stale _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_unlocked(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); +} + void acpi_ec_block_transactions(void) { struct acpi_ec *ec = first_ec; @@ -463,6 +489,10 @@ void acpi_ec_unblock_transactions(void) mutex_lock(&ec->mutex); /* Allow transactions to be carried out again */ clear_bit(EC_FLAGS_BLOCKED, &ec->flags); + + if (EC_FLAGS_CLEAR_ON_RESUME) + acpi_ec_clear(ec); + mutex_unlock(&ec->mutex); } @@ -821,6 +851,13 @@ static int acpi_ec_add(struct acpi_device *device) /* EC is fully operational, allow queries */ clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); + + /* Clear stale _Q events if hardware might require that */ + if (EC_FLAGS_CLEAR_ON_RESUME) { + mutex_lock(&ec->mutex); + acpi_ec_clear(ec); + mutex_unlock(&ec->mutex); + } return ret; } @@ -922,6 +959,30 @@ static int ec_enlarge_storm_threshold(const struct dmi_system_id *id) return 0; } +/* + * 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; + return 0; +} + static struct dmi_system_id ec_dmi_table[] __initdata = { { ec_skip_dsdt_scan, "Compal JFL92", { @@ -965,6 +1026,9 @@ static struct dmi_system_id ec_dmi_table[] __initdata = { ec_validate_ecdt, "ASUS hardware", { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."), DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL}, + { + ec_clear_on_resume, "Samsung hardware", { + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL}, {}, }; |