ACPI: EC: Workaround for optimized controllers (version 3)

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

Reference: 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>
Tested-by: Mats Johannesson
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 33 insertions, 13 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index d5a5958d4b20..7d6b84119792 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -78,7 +78,10 @@ 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 */
+        EC_FLAGS_NO_WDATA_GPE,          /* Don't expect WDATA GPE event */
+        EC_FLAGS_WDATA,                 /* Data is being written */
 };
 
 static int acpi_ec_remove(struct acpi_device *device, int type);
@@ -175,39 +178,54 @@ 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 (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
+                     test_bit(EC_FLAGS_NO_WDATA_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 */
-                                pr_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 */
+                                pr_info(PREFIX "missing address confirmation, "
+                                        "don't expect it any longer.\n");
+                                set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
+                        } else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
+                                /* miss write data GPE, don't expect it */
+                                pr_info(PREFIX "missing write data confirmation, "
+                                        "don't expect it any longer.\n");
+                                set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
                         } else {
                                 /* missing GPEs, switch back to poll mode */
                                 if (printk_ratelimit())
-                                        pr_info(PREFIX "missing IBF_1 confirmations,"
+                                        pr_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;
                 }
         }
         pr_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,
@@ -226,11 +244,15 @@ 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++));
         }
 
         if (!rdata_len) {
+                set_bit(EC_FLAGS_WDATA, &ec->flags);
                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
                 if (result) {
                         pr_err(PREFIX
@@ -241,8 +263,6 @@ 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) {
                         pr_err(PREFIX "read timeout, command = %d\n", command);