ACPI / EC: Add more debug info and trivial code cleanup

commit b76b51ba0cef13980813373a548a12206e3cd3c9 upstream.

Add more debug info for EC transaction debugging, like the interrupt
status register value, the detail info of a EC transaction.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 3923064..75a12f1 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -178,30 +178,32 @@ static void start_transaction(struct acpi_ec *ec)
 static void advance_transaction(struct acpi_ec *ec, u8 status)
 {
        unsigned long flags;
+       struct transaction *t = ec->curr;
+
        spin_lock_irqsave(&ec->curr_lock, flags);
-       if (!ec->curr)
+       if (!t)
                goto unlock;
-       if (ec->curr->wlen > ec->curr->wi) {
+       if (t->wlen > t->wi) {
                if ((status & ACPI_EC_FLAG_IBF) == 0)
                        acpi_ec_write_data(ec,
-                               ec->curr->wdata[ec->curr->wi++]);
+                               t->wdata[t->wi++]);
                else
                        goto err;
-       } else if (ec->curr->rlen > ec->curr->ri) {
+       } else if (t->rlen > t->ri) {
                if ((status & ACPI_EC_FLAG_OBF) == 1) {
-                       ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
-                       if (ec->curr->rlen == ec->curr->ri)
-                               ec->curr->done = true;
+                       t->rdata[t->ri++] = acpi_ec_read_data(ec);
+                       if (t->rlen == t->ri)
+                               t->done = true;
                } else
                        goto err;
-       } else if (ec->curr->wlen == ec->curr->wi &&
+       } else if (t->wlen == t->wi &&
                   (status & ACPI_EC_FLAG_IBF) == 0)
-               ec->curr->done = true;
+               t->done = true;
        goto unlock;
 err:
        /* false interrupt, state didn't change */
        if (in_interrupt())
-               ++ec->curr->irq_count;
+               ++t->irq_count;
 unlock:
        spin_unlock_irqrestore(&ec->curr_lock, flags);
 }
@@ -311,7 +313,8 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
                status = -ETIME;
                goto end;
        }
-       pr_debug(PREFIX "transaction start\n");
+       pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
+                       t->command, t->wdata ? t->wdata[0] : 0);
        /* disable GPE during transaction if storm is detected */
        if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
                /* It has to be disabled, so that it doesn't trigger. */
@@ -327,8 +330,9 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
                /* It is safe to enable the GPE outside of the transaction. */
                acpi_enable_gpe(NULL, ec->gpe);
        } else if (t->irq_count > ec_storm_threshold) {
-               pr_info(PREFIX "GPE storm detected, "
-                       "transactions will use polling mode\n");
+               pr_info(PREFIX "GPE storm detected(%d GPEs), "
+                       "transactions will use polling mode\n",
+                       t->irq_count);
                set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
        }
        pr_debug(PREFIX "transaction end\n");
@@ -404,7 +408,7 @@ int ec_burst_disable(void)
 
 EXPORT_SYMBOL(ec_burst_disable);
 
-int ec_read(u8 addr, u8 * val)
+int ec_read(u8 addr, u8 *val)
 {
        int err;
        u8 temp_data;
@@ -643,10 +647,11 @@ static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
        u32 gpe_number, void *data)
 {
        struct acpi_ec *ec = data;
+       u8 status = acpi_ec_read_status(ec);
 
-       pr_debug(PREFIX "~~~> interrupt\n");
+       pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
 
-       advance_transaction(ec, acpi_ec_read_status(ec));
+       advance_transaction(ec, status);
        if (ec_transaction_done(ec) &&
            (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
                wake_up(&ec->wait);