From 34ff4dbccccce54c83b1234d39b7ad9e548a75dd Mon Sep 17 00:00:00 2001 From: Alexey Starikovskiy Date: Wed, 1 Apr 2009 00:25:10 -0400 Subject: [PATCH] ACPI: EC: Separate delays for MSI hardware MSI notebooks require very strict delays, while all others are happy with msleep(). References: http://bugzilla.kernel.org/show_bug.cgi?id=9998 Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/ec.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 2fe15060dcdc..ac9dd3b386b1 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -67,7 +67,7 @@ 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_UDELAY 100 /* Wait 100us before polling EC again */ +#define ACPI_EC_CDELAY 10 /* Wait 10us before polling EC */ #define ACPI_EC_STORM_THRESHOLD 8 /* number of false interrupts per one transaction */ @@ -236,13 +236,23 @@ static int ec_check_sci(struct acpi_ec *ec, u8 state) return 0; } +static void ec_delay(void) +{ + /* EC in MSI notebooks don't tolerate delays other than 550 usec */ + if (EC_FLAGS_MSI) + udelay(ACPI_EC_DELAY); + else + /* Use shortest sleep available */ + msleep(1); +} + static int ec_poll(struct acpi_ec *ec) { unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY); - udelay(ACPI_EC_UDELAY); + udelay(ACPI_EC_CDELAY); while (time_before(jiffies, delay)) { gpe_transaction(ec, acpi_ec_read_status(ec)); - udelay(ACPI_EC_UDELAY); + ec_delay(); if (ec_transaction_done(ec)) return 0; }