From 7a18e96dcbdec3c96876444ae2c7e36ce458e151 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Thu, 21 Oct 2010 18:24:57 +0200 Subject: [PATCH] ACPI: Make Embedded Controller command timeout delay configurable Here and then there show up machines which need higher timeout values. Finding this on affected machines can be cumbersome, because ACPI_EC_DELAY is a compile option -> make it configurable via boot param. This can even be provided writable at runtime via: /sys/modules/acpi/parameters/ec_delay Known machines where this helps: Some HP machines where for whatever reasons specific EC accesses take very long at resume from S3 (in _WAK function). The AE_TIME error is passed upwards and the ACPI interpreter will not execute the rest of the _WAK function which results in not properly initialized devices/variables with different side-effects. Afaik, on some MSI machines this helped as well. If this param is needed there probably are underlying problems like: - EC firmware bug - A kernel EC driver bug - An ACPI interpreter behavior (e.g. timings when specific EC accesses happen and how) which the EC does not like - ... which should get evaluated further, but often are nasty or impossible to fix from OS side. Signed-off-by: Thomas Renninger Signed-off-by: Len Brown --- drivers/acpi/ec.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index f31291ba94d..372ff80b7b0 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -83,6 +83,11 @@ enum { EC_FLAGS_BLOCKED, /* Transactions are blocked */ }; +/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */ +static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY; +module_param(ec_delay, uint, 0644); +MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes"); + /* If we find an EC via the ECDT, we need to keep a ptr to its context */ /* External interfaces use first EC only, so remember */ typedef int (*acpi_ec_query_func) (void *data); @@ -210,7 +215,7 @@ static int ec_poll(struct acpi_ec *ec) int repeat = 2; /* number of command restarts */ while (repeat--) { unsigned long delay = jiffies + - msecs_to_jiffies(ACPI_EC_DELAY); + msecs_to_jiffies(ec_delay); do { /* don't sleep with disabled interrupts */ if (EC_FLAGS_MSI || irqs_disabled()) { @@ -265,7 +270,7 @@ static int ec_check_ibf0(struct acpi_ec *ec) static int ec_wait_ibf0(struct acpi_ec *ec) { - unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY); + unsigned long delay = jiffies + msecs_to_jiffies(ec_delay); /* interrupt wait manually if GPE mode is not active */ while (time_before(jiffies, delay)) if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), -- 2.11.4.GIT