ACPI: EC: Add workaround for "optimized" controllers

Some controllers do not send interrupts for OBF=1 event, but send
them for IBF=0. Add workaround for them.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=8459

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 41a21fc..202db57 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -75,6 +75,7 @@ enum {
        EC_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
        EC_FLAGS_QUERY_PENDING,         /* Query is pending */
        EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
+       EC_FLAGS_ONLY_IBF_GPE,          /* Expect GPE only for IBF = 0 event */
 };
 
 static int acpi_ec_remove(struct acpi_device *device, int type);
@@ -172,7 +173,12 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
                        return 0;
                clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                if (acpi_ec_check_status(ec, event)) {
-                       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+                       if (event == ACPI_EC_EVENT_OBF_1)
+                               /* miss OBF = 1 GPE, don't expect it anymore */
+                               set_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags);
+                       else
+                               /* missing GPEs, switch back to poll mode */
+                               clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
                        return 0;
                }
        } else {
@@ -220,6 +226,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
                clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 
        for (; rdata_len > 0; --rdata_len) {
+               if (test_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags))
+                       force_poll = 1;
                result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
                if (result) {
                        printk(KERN_ERR PREFIX "read timeout, command = %d\n",