net: ipa: further simplify gsi_channel_trans_last()

Do a little more refactoring in gsi_channel_trans_last() to simplify
it further.  The resulting code should behave exactly as before.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 841a946bc286a5b7717bf6c5030bfc9cb3bb2f6a..16df699009a86a1158415955cbc5d3f5062fbedc 100644 (file)
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -710,42 +710,32 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id)
 static struct gsi_trans *gsi_channel_trans_last(struct gsi_channel *channel)
 {
        struct gsi_trans_info *trans_info = &channel->trans_info;
+       u32 pending_id = trans_info->pending_id;
        struct gsi_trans *trans;
-       u16 trans_index;
        u16 trans_id;
 
-       /* There is a small chance a TX transaction got allocated just
-        * before we disabled transmits, so check for that.
-        */
-       if (channel->toward_ipa) {
-               /* The last allocated, committed, or pending transaction
+       if (channel->toward_ipa && pending_id != trans_info->free_id) {
+               /* There is a small chance a TX transaction got allocated
+                * just before we disabled transmits, so check for that.
+                * The last allocated, committed, or pending transaction
                 * precedes the first free transaction.
                 */
-               if (trans_info->pending_id != trans_info->free_id) {
-                       trans_id = trans_info->free_id - 1;
-                       trans_index = trans_id % channel->tre_count;
-                       trans = &trans_info->trans[trans_index];
-                       goto done;
-               }
-       }
-
-       /* Otherwise (TX or RX) we want to wait for anything that
-        * has completed, or has been polled but not released yet.
-        *
-        * The last completed or polled transaction precedes the
-        * first pending transaction.
-        */
-       if (trans_info->polled_id != trans_info->pending_id) {
-               trans_id = trans_info->pending_id - 1;
-               trans_index = trans_id % channel->tre_count;
-               trans = &trans_info->trans[trans_index];
+               trans_id = trans_info->free_id - 1;
+       } else if (trans_info->polled_id != pending_id) {
+               /* Otherwise (TX or RX) we want to wait for anything that
+                * has completed, or has been polled but not released yet.
+                *
+                * The last completed or polled transaction precedes the
+                * first pending transaction.
+                */
+               trans_id = pending_id - 1;
        } else {
-               trans = NULL;
+               return NULL;
        }
-done:
+
        /* Caller will wait for this, so take a reference */
-       if (trans)
-               refcount_inc(&trans->refcount);
+       trans = &trans_info->trans[trans_id % channel->tre_count];
+       refcount_inc(&trans->refcount);
 
        return trans;
 }