ACPI: EC: Drop orphan comment
[sfrench/cifs-2.6.git] / drivers / acpi / ec.c
index 391f331674c74c812fddce14203073ceb083a2dd..dc5561809529c4a2c09eb15828582878c2589826 100644 (file)
@@ -68,15 +68,13 @@ enum ec_command {
 #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_CDELAY         10      /* Wait 10us before polling EC */
+#define ACPI_EC_MSI_UDELAY     550     /* Wait 550us for MSI EC */
 
 #define ACPI_EC_STORM_THRESHOLD 8      /* number of false interrupts
                                           per one transaction */
 
 enum {
        EC_FLAGS_QUERY_PENDING,         /* Query is pending */
-       EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
-                                        * for status change */
-       EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
        EC_FLAGS_GPE_STORM,             /* GPE storm detected */
        EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
                                         * OpReg are installed */
@@ -170,7 +168,7 @@ static void start_transaction(struct acpi_ec *ec)
        acpi_ec_write_cmd(ec, ec->curr->command);
 }
 
-static void gpe_transaction(struct acpi_ec *ec, u8 status)
+static void advance_transaction(struct acpi_ec *ec, u8 status)
 {
        unsigned long flags;
        spin_lock_irqsave(&ec->curr_lock, flags);
@@ -201,29 +199,6 @@ unlock:
        spin_unlock_irqrestore(&ec->curr_lock, flags);
 }
 
-static int acpi_ec_wait(struct acpi_ec *ec)
-{
-       if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
-                              msecs_to_jiffies(ACPI_EC_DELAY)))
-               return 0;
-       /* try restart command if we get any false interrupts */
-       if (ec->curr->irq_count &&
-           (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
-               pr_debug(PREFIX "controller reset, restart transaction\n");
-               start_transaction(ec);
-               if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
-                                       msecs_to_jiffies(ACPI_EC_DELAY)))
-                       return 0;
-       }
-       /* missing GPEs, switch back to poll mode */
-       if (printk_ratelimit())
-               pr_info(PREFIX "missing confirmations, "
-                               "switch off interrupt mode.\n");
-       set_bit(EC_FLAGS_NO_GPE, &ec->flags);
-       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
-       return 1;
-}
-
 static void acpi_ec_gpe_query(void *ec_cxt);
 
 static int ec_check_sci(struct acpi_ec *ec, u8 state)
@@ -236,43 +211,51 @@ static int ec_check_sci(struct acpi_ec *ec, u8 state)
        return 0;
 }
 
-static void ec_delay(void)
-{
-       /* EC in MSI notebooks don't tolerate delays other than 550 usec */
-       if (EC_FLAGS_MSI)
-               udelay(ACPI_EC_DELAY);
-       else
-               /* Use shortest sleep available */
-               msleep(1);
-}
-
 static int ec_poll(struct acpi_ec *ec)
 {
-       unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
-       udelay(ACPI_EC_CDELAY);
-       while (time_before(jiffies, delay)) {
-               gpe_transaction(ec, acpi_ec_read_status(ec));
-               ec_delay();
-               if (ec_transaction_done(ec))
-                       return 0;
+       unsigned long flags;
+       int repeat = 2; /* number of command restarts */
+       while (repeat--) {
+               unsigned long delay = jiffies +
+                       msecs_to_jiffies(ACPI_EC_DELAY);
+               do {
+                       /* don't sleep with disabled interrupts */
+                       if (EC_FLAGS_MSI || irqs_disabled()) {
+                               udelay(ACPI_EC_MSI_UDELAY);
+                               if (ec_transaction_done(ec))
+                                       return 0;
+                       } else {
+                               if (wait_event_timeout(ec->wait,
+                                               ec_transaction_done(ec),
+                                               msecs_to_jiffies(1)))
+                                       return 0;
+                       }
+                       advance_transaction(ec, acpi_ec_read_status(ec));
+               } while (time_before(jiffies, delay));
+               if (!ec->curr->irq_count ||
+                   (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
+                       break;
+               /* try restart command if we get any false interrupts */
+               pr_debug(PREFIX "controller reset, restart transaction\n");
+               spin_lock_irqsave(&ec->curr_lock, flags);
+               start_transaction(ec);
+               spin_unlock_irqrestore(&ec->curr_lock, flags);
        }
        return -ETIME;
 }
 
 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
-                                       struct transaction *t,
-                                       int force_poll)
+                                       struct transaction *t)
 {
        unsigned long tmp;
        int ret = 0;
        pr_debug(PREFIX "transaction start\n");
        /* disable GPE during transaction if storm is detected */
        if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
-               clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
                acpi_disable_gpe(NULL, ec->gpe);
        }
        if (EC_FLAGS_MSI)
-               udelay(ACPI_EC_DELAY);
+               udelay(ACPI_EC_MSI_UDELAY);
        /* start transaction */
        spin_lock_irqsave(&ec->curr_lock, tmp);
        /* following two actions should be kept atomic */
@@ -281,11 +264,7 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
        if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
                clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
        spin_unlock_irqrestore(&ec->curr_lock, tmp);
-       /* if we selected poll mode or failed in GPE-mode do a poll loop */
-       if (force_poll ||
-           !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
-           acpi_ec_wait(ec))
-               ret = ec_poll(ec);
+       ret = ec_poll(ec);
        pr_debug(PREFIX "transaction end\n");
        spin_lock_irqsave(&ec->curr_lock, tmp);
        ec->curr = NULL;
@@ -295,8 +274,7 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
                ec_check_sci(ec, acpi_ec_read_status(ec));
                /* it is safe to enable GPE outside of transaction */
                acpi_enable_gpe(NULL, ec->gpe);
-       } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
-                  t->irq_count > ACPI_EC_STORM_THRESHOLD) {
+       } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
                pr_info(PREFIX "GPE storm detected, "
                        "transactions will use polling mode\n");
                set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
@@ -314,16 +292,14 @@ static int ec_wait_ibf0(struct acpi_ec *ec)
 {
        unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
        /* interrupt wait manually if GPE mode is not active */
-       unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
-               msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
        while (time_before(jiffies, delay))
-               if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
+               if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
+                                       msecs_to_jiffies(1)))
                        return 0;
        return -ETIME;
 }
 
-static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
-                              int force_poll)
+static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 {
        int status;
        u32 glk;
@@ -345,7 +321,7 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
                status = -ETIME;
                goto end;
        }
-       status = acpi_ec_transaction_unlocked(ec, t, force_poll);
+       status = acpi_ec_transaction_unlocked(ec, t);
 end:
        if (ec->global_lock)
                acpi_release_global_lock(glk);
@@ -354,10 +330,6 @@ unlock:
        return status;
 }
 
-/*
- * Note: samsung nv5000 doesn't work with ec burst mode.
- * http://bugzilla.kernel.org/show_bug.cgi?id=4980
- */
 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 {
        u8 d;
@@ -365,7 +337,7 @@ static int acpi_ec_burst_enable(struct acpi_ec *ec)
                                .wdata = NULL, .rdata = &d,
                                .wlen = 0, .rlen = 1};
 
-       return acpi_ec_transaction(ec, &t, 0);
+       return acpi_ec_transaction(ec, &t);
 }
 
 static int acpi_ec_burst_disable(struct acpi_ec *ec)
@@ -375,7 +347,7 @@ static int acpi_ec_burst_disable(struct acpi_ec *ec)
                                .wlen = 0, .rlen = 0};
 
        return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
-                               acpi_ec_transaction(ec, &t, 0) : 0;
+                               acpi_ec_transaction(ec, &t) : 0;
 }
 
 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
@@ -386,7 +358,7 @@ static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
                                .wdata = &address, .rdata = &d,
                                .wlen = 1, .rlen = 1};
 
-       result = acpi_ec_transaction(ec, &t, 0);
+       result = acpi_ec_transaction(ec, &t);
        *data = d;
        return result;
 }
@@ -398,7 +370,7 @@ static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
                                .wdata = wdata, .rdata = NULL,
                                .wlen = 2, .rlen = 0};
 
-       return acpi_ec_transaction(ec, &t, 0);
+       return acpi_ec_transaction(ec, &t);
 }
 
 /*
@@ -466,7 +438,7 @@ int ec_transaction(u8 command,
        if (!first_ec)
                return -ENODEV;
 
-       return acpi_ec_transaction(first_ec, &t, force_poll);
+       return acpi_ec_transaction(first_ec, &t);
 }
 
 EXPORT_SYMBOL(ec_transaction);
@@ -487,7 +459,7 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
         * bit to be cleared (and thus clearing the interrupt source).
         */
 
-       result = acpi_ec_transaction(ec, &t, 0);
+       result = acpi_ec_transaction(ec, &t);
        if (result)
                return result;
 
@@ -570,28 +542,10 @@ static u32 acpi_ec_gpe_handler(void *data)
        pr_debug(PREFIX "~~~> interrupt\n");
        status = acpi_ec_read_status(ec);
 
-       if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
-               gpe_transaction(ec, status);
-               if (ec_transaction_done(ec) &&
-                   (status & ACPI_EC_FLAG_IBF) == 0)
-                       wake_up(&ec->wait);
-       }
-
+       advance_transaction(ec, status);
+       if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
+               wake_up(&ec->wait);
        ec_check_sci(ec, status);
-       if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
-           !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
-               /* this is non-query, must be confirmation */
-               if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
-                       if (printk_ratelimit())
-                               pr_info(PREFIX "non-query interrupt received,"
-                                       " switching to interrupt mode\n");
-               } else {
-                       /* hush, STORM switches the mode every transaction */
-                       pr_debug(PREFIX "non-query interrupt received,"
-                               " switching to interrupt mode\n");
-               }
-               set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
-       }
        return ACPI_INTERRUPT_HANDLED;
 }
 
@@ -617,7 +571,8 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
        if (bits != 8 && acpi_strict)
                return AE_BAD_PARAMETER;
 
-       acpi_ec_burst_enable(ec);
+       if (EC_FLAGS_MSI)
+               acpi_ec_burst_enable(ec);
 
        if (function == ACPI_READ) {
                result = acpi_ec_read(ec, address, &temp);
@@ -638,7 +593,8 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
                }
        }
 
-       acpi_ec_burst_disable(ec);
+       if (EC_FLAGS_MSI)
+               acpi_ec_burst_disable(ec);
 
        switch (result) {
        case -EINVAL:
@@ -837,8 +793,6 @@ static int acpi_ec_add(struct acpi_device *device)
        acpi_ec_add_fs(device);
        pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
                          ec->gpe, ec->command_addr, ec->data_addr);
-       pr_info(PREFIX "driver started in %s mode\n",
-               (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
        return 0;
 }
 
@@ -1054,8 +1008,6 @@ static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
 {
        struct acpi_ec *ec = acpi_driver_data(device);
        /* Stop using GPE */
-       set_bit(EC_FLAGS_NO_GPE, &ec->flags);
-       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
        acpi_disable_gpe(NULL, ec->gpe);
        return 0;
 }
@@ -1064,8 +1016,6 @@ static int acpi_ec_resume(struct acpi_device *device)
 {
        struct acpi_ec *ec = acpi_driver_data(device);
        /* Enable use of GPE back */
-       clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
-       set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
        acpi_enable_gpe(NULL, ec->gpe);
        return 0;
 }