Merge tag 'powerpc-5.13-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
[linux-2.6-microblaze.git] / drivers / acpi / ec.c
index e0cb1bc..1356562 100644 (file)
@@ -169,7 +169,7 @@ struct acpi_ec_query {
 };
 
 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
-static void advance_transaction(struct acpi_ec *ec);
+static void advance_transaction(struct acpi_ec *ec, bool interrupt);
 static void acpi_ec_event_handler(struct work_struct *work);
 static void acpi_ec_event_processor(struct work_struct *work);
 
@@ -335,12 +335,12 @@ static const char *acpi_ec_cmd_string(u8 cmd)
  *                           GPE Registers
  * -------------------------------------------------------------------------- */
 
-static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
+static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
 {
        acpi_event_status gpe_status = 0;
 
        (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
-       return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
+       return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
 }
 
 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
@@ -351,14 +351,14 @@ static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
                BUG_ON(ec->reference_count < 1);
                acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
        }
-       if (acpi_ec_is_gpe_raised(ec)) {
+       if (acpi_ec_gpe_status_set(ec)) {
                /*
                 * On some platforms, EN=1 writes cannot trigger GPE. So
                 * software need to manually trigger a pseudo GPE event on
                 * EN=1 writes.
                 */
                ec_dbg_raw("Polling quirk");
-               advance_transaction(ec);
+               advance_transaction(ec, false);
        }
 }
 
@@ -372,23 +372,6 @@ static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
        }
 }
 
-static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
-{
-       /*
-        * GPE STS is a W1C register, which means:
-        * 1. Software can clear it without worrying about clearing other
-        *    GPEs' STS bits when the hardware sets them in parallel.
-        * 2. As long as software can ensure only clearing it when it is
-        *    set, hardware won't set it in parallel.
-        * So software can clear GPE in any contexts.
-        * Warning: do not move the check into advance_transaction() as the
-        * EC commands will be sent without GPE raised.
-        */
-       if (!acpi_ec_is_gpe_raised(ec))
-               return;
-       acpi_clear_gpe(NULL, ec->gpe);
-}
-
 /* --------------------------------------------------------------------------
  *                           Transaction Management
  * -------------------------------------------------------------------------- */
@@ -488,7 +471,7 @@ static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
         * Unconditionally invoke this once after enabling the event
         * handling mechanism to detect the pending events.
         */
-       advance_transaction(ec);
+       advance_transaction(ec, false);
 }
 
 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
@@ -632,24 +615,41 @@ static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long f
        }
 }
 
-static void advance_transaction(struct acpi_ec *ec)
+static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
 {
-       struct transaction *t;
-       u8 status;
+       if (t->irq_count < ec_storm_threshold)
+               ++t->irq_count;
+
+       /* Trigger if the threshold is 0 too. */
+       if (t->irq_count == ec_storm_threshold)
+               acpi_ec_mask_events(ec);
+}
+
+static void advance_transaction(struct acpi_ec *ec, bool interrupt)
+{
+       struct transaction *t = ec->curr;
        bool wakeup = false;
+       u8 status;
+
+       ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 
-       ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
-                  smp_processor_id());
        /*
-        * By always clearing STS before handling all indications, we can
-        * ensure a hardware STS 0->1 change after this clearing can always
-        * trigger a GPE interrupt.
+        * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
+        * changes to always trigger a GPE interrupt.
+        *
+        * GPE STS is a W1C register, which means:
+        *
+        * 1. Software can clear it without worrying about clearing the other
+        *    GPEs' STS bits when the hardware sets them in parallel.
+        *
+        * 2. As long as software can ensure only clearing it when it is set,
+        *    hardware won't set it in parallel.
         */
-       if (ec->gpe >= 0)
-               acpi_ec_clear_gpe(ec);
+       if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
+               acpi_clear_gpe(NULL, ec->gpe);
 
        status = acpi_ec_read_status(ec);
-       t = ec->curr;
+
        /*
         * Another IRQ or a guarded polling mode advancement is detected,
         * the next QR_EC submission is then allowed.
@@ -661,56 +661,43 @@ static void advance_transaction(struct acpi_ec *ec)
                        clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
                        acpi_ec_complete_query(ec);
                }
+               if (!t)
+                       goto out;
        }
-       if (!t)
-               goto err;
+
        if (t->flags & ACPI_EC_COMMAND_POLL) {
                if (t->wlen > t->wi) {
-                       if ((status & ACPI_EC_FLAG_IBF) == 0)
+                       if (!(status & ACPI_EC_FLAG_IBF))
                                acpi_ec_write_data(ec, t->wdata[t->wi++]);
-                       else
-                               goto err;
+                       else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
+                               acpi_ec_spurious_interrupt(ec, t);
                } else if (t->rlen > t->ri) {
-                       if ((status & ACPI_EC_FLAG_OBF) == 1) {
+                       if (status & ACPI_EC_FLAG_OBF) {
                                t->rdata[t->ri++] = acpi_ec_read_data(ec);
                                if (t->rlen == t->ri) {
                                        ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
+                                       wakeup = true;
                                        if (t->command == ACPI_EC_COMMAND_QUERY)
                                                ec_dbg_evt("Command(%s) completed by hardware",
                                                           acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
-                                       wakeup = true;
                                }
-                       } else
-                               goto err;
-               } else if (t->wlen == t->wi &&
-                          (status & ACPI_EC_FLAG_IBF) == 0) {
+                       } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
+                               acpi_ec_spurious_interrupt(ec, t);
+                       }
+               } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
                        ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
                        wakeup = true;
                }
-               goto out;
        } else if (!(status & ACPI_EC_FLAG_IBF)) {
                acpi_ec_write_cmd(ec, t->command);
                ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
-               goto out;
-       }
-err:
-       /*
-        * If SCI bit is set, then don't think it's a false IRQ
-        * otherwise will take a not handled IRQ as a false one.
-        */
-       if (!(status & ACPI_EC_FLAG_SCI)) {
-               if (in_interrupt() && t) {
-                       if (t->irq_count < ec_storm_threshold)
-                               ++t->irq_count;
-                       /* Allow triggering on 0 threshold */
-                       if (t->irq_count == ec_storm_threshold)
-                               acpi_ec_mask_events(ec);
-               }
        }
+
 out:
        if (status & ACPI_EC_FLAG_SCI)
                acpi_ec_submit_query(ec);
-       if (wakeup && in_interrupt())
+
+       if (wakeup && interrupt)
                wake_up(&ec->wait);
 }
 
@@ -767,7 +754,7 @@ static int ec_poll(struct acpi_ec *ec)
                        if (!ec_guard(ec))
                                return 0;
                        spin_lock_irqsave(&ec->lock, flags);
-                       advance_transaction(ec);
+                       advance_transaction(ec, false);
                        spin_unlock_irqrestore(&ec->lock, flags);
                } while (time_before(jiffies, delay));
                pr_debug("controller reset, restart transaction\n");
@@ -1216,7 +1203,7 @@ static void acpi_ec_check_event(struct acpi_ec *ec)
                         * taking care of it.
                         */
                        if (!ec->curr)
-                               advance_transaction(ec);
+                               advance_transaction(ec, false);
                        spin_unlock_irqrestore(&ec->lock, flags);
                }
        }
@@ -1259,7 +1246,7 @@ static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
        unsigned long flags;
 
        spin_lock_irqsave(&ec->lock, flags);
-       advance_transaction(ec);
+       advance_transaction(ec, true);
        spin_unlock_irqrestore(&ec->lock, flags);
 }