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 <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 2fe1506..ac9dd3b 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -67,7 +67,7 @@
#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 @@
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;
}