ACPI: EC: Restore udelay in poll mode
This fixes keyboard event handling on some systems.
Note that this delay was thought unnecessary, and removed
from linux-2.6.20 with 50c1e1138cb94f6aca0f8555777edbcefe0324e2
'ACPI: ec: Drop udelay() from poll mode. Loop by reading status field instead.'
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 7222a18..828c752 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -73,6 +73,7 @@
#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 */
enum {
EC_FLAGS_WAIT_GPE = 0, /* Don't check status until GPE arrives */
@@ -227,6 +228,7 @@
while (time_before(jiffies, delay)) {
if (acpi_ec_check_status(ec, event))
goto end;
+ udelay(ACPI_EC_UDELAY);
}
}
pr_err(PREFIX "acpi_ec_wait timeout,"