ACPI: EC: Simplify error handling in advance_transaction()

Notice that the value of t in advance_transaction() does not change
after its initialization and:

 - Initialize t upfront (and rearrange the definitions of local
   variables while at it).

 - Check it against NULL in a block executed when it is NULL.

 - Skip error handling for t == NULL, because a valid pointer value
   of t is required for the error handling.

 - Drop the (now redundant) check of t against NULL from the error
   handling block and reduce the indentation level in there.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index c4be16a..23e7b2d 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -617,9 +617,9 @@ static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long f
 
 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
 {
-       struct transaction *t;
-       u8 status;
+       struct transaction *t = ec->curr;
        bool wakeup = false;
+       u8 status;
 
        ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 
@@ -639,7 +639,7 @@ static void advance_transaction(struct acpi_ec *ec, bool interrupt)
                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.
@@ -651,9 +651,10 @@ static void advance_transaction(struct acpi_ec *ec, bool interrupt)
                        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)
@@ -688,14 +689,13 @@ 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 (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);
-               }
+       if (!(status & ACPI_EC_FLAG_SCI) && interrupt) {
+               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)