slimbus: messaging: start transaction ids from 1 instead of zero

[ Upstream commit 9659281 ]

As tid is unsigned its hard to figure out if the tid is valid or
invalid. So Start the transaction ids from 1 instead of zero
so that we could differentiate between a valid tid and invalid tids

This is useful in cases where controller would add a tid for controller
specific transfers.

Fixes: d3062a2 ("slimbus: messaging: add slim_alloc/free_txn_tid()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210809082428.11236-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/slimbus/messaging.c

@@ -66,7 +66,7 @@ int slim_alloc_txn_tid(struct slim_controller *ctrl, struct slim_msg_txn *txn)
 	int ret = 0;
 
 	spin_lock_irqsave(&ctrl->txn_lock, flags);
-	ret = idr_alloc_cyclic(&ctrl->tid_idr, txn, 0,
+	ret = idr_alloc_cyclic(&ctrl->tid_idr, txn, 1,
 				SLIM_MAX_TIDS, GFP_ATOMIC);
 	if (ret < 0) {
 		spin_unlock_irqrestore(&ctrl->txn_lock, flags);