ACPI: EC: Workaround for optimized controllers

Some controllers fail to send confirmation GPE after address write.
Detect this and don't expect such confirmation in future.
This is a generalization of previous workaround
(66c5f4e7367b0085652931b2f3366de29e7ff5ec), which did only read address.

http://bugzilla.kernel.org/show_bug.cgi?id=9327

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: Romano Giannetti <romano.giannetti@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 06b78e5..390f8f8 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -75,7 +75,8 @@ 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 */
+       EC_FLAGS_NO_ADDRESS_GPE,        /* Expect GPE only for non-address event */
+       EC_FLAGS_ADDRESS,               /* Address is being written */
 };
 
 static int acpi_ec_remove(struct acpi_device *device, int type);
@@ -166,38 +167,45 @@ static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 
 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
+       int ret = 0;
+       if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
+                    test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
+               force_poll = 1;
        if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
            likely(!force_poll)) {
                if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
                                       msecs_to_jiffies(ACPI_EC_DELAY)))
-                       return 0;
+                       goto end;
                clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                if (acpi_ec_check_status(ec, event)) {
-                       if (event == ACPI_EC_EVENT_OBF_1) {
-                               /* miss OBF = 1 GPE, don't expect it anymore */
-                               printk(KERN_INFO PREFIX "missing OBF_1 confirmation,"
-                                       "switching to degraded mode.\n");
-                               set_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags);
+                       if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
+                               /* miss address GPE, don't expect it anymore */
+                               printk(KERN_INFO PREFIX "missing address confirmation,"
+                                       "don't expect it any longer.\n");
+                               set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
                        } else {
                                /* missing GPEs, switch back to poll mode */
-                               printk(KERN_INFO PREFIX "missing IBF_1 confirmations,"
+                               printk(KERN_INFO PREFIX "missing confirmations,"
                                        "switch off interrupt mode.\n");
                                clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
                        }
-                       return 0;
+                       goto end;
                }
        } else {
                unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
                clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                while (time_before(jiffies, delay)) {
                        if (acpi_ec_check_status(ec, event))
-                               return 0;
+                               goto end;
                }
        }
        printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
                               " status = %d, expect_event = %d\n",
                               acpi_ec_read_status(ec), event);
-       return -ETIME;
+       ret = -ETIME;
+      end:
+       clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
+       return ret;
 }
 
 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
@@ -216,6 +224,9 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
                               "write_cmd timeout, command = %d\n", command);
                        goto end;
                }
+               /* mark the address byte written to EC */
+               if (rdata_len + wdata_len > 1)
+                       set_bit(EC_FLAGS_ADDRESS, &ec->flags);
                set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                acpi_ec_write_data(ec, *(wdata++));
        }
@@ -231,8 +242,6 @@ 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",