From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> stable inclusion from linux-4.19.205 commit ea99a7fae21b554d50880d3392122ffce14615ef -------------------------------- [ Upstream commit 9659281ce78de0f15a4aa124da8f7450b1399c09 ] 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: d3062a210930 ("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.... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/slimbus/messaging.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/slimbus/messaging.c b/drivers/slimbus/messaging.c index d5879142dbef1..3b77713f1e3fb 100644 --- a/drivers/slimbus/messaging.c +++ b/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); -- 2.25.1