[PATCH 5.4 285/320] Revert "net/mlx5: Add retry mechanism to the command entry index allocation"

Greg Kroah-Hartman
2022-01-25T03:24:34Z

From: Moshe Shemesh <moshe@nvidia.com>

commit 4f6626b0e140867fd6d5a2e9d4ceaef97f10f46a upstream.

This reverts commit 410bd754cd73c4a2ac3856d9a03d7b08f9c906bf.

The reverted commit had added a retry mechanism to the command entry
index allocation. The previous patch ensures that there is a free
command entry index once the command work handler holds the command
semaphore. Thus the retry mechanism is not needed.

Fixes: 410bd754cd73 ("net/mlx5: Add retry mechanism to the command entry index allocation")
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Eran Ben Elisha <eranbe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 21 +--------------------
1 file changed, 1 insertion(+), 20 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -887,25 +887,6 @@ static bool opcode_allowed(struct mlx5_c
return cmd->allowed_opcode == opcode;
}

-static int cmd_alloc_index_retry(struct mlx5_cmd *cmd)
-{
- unsigned long alloc_end = jiffies + msecs_to_jiffies(1000);
- int idx;
-
-retry:
- idx = cmd_alloc_index(cmd);
- if (idx < 0 && time_before(jiffies, alloc_end)) {
- /* Index allocation can fail on heavy load of commands. This is a temporary
- * situation as the current command already holds the semaphore, meaning that
- * another command completion is being handled and it is expected to release
- * the entry index soon.
- */
- cpu_relax();
- goto retry;
- }
- return idx;
-}
-
static void cmd_work_handler(struct work_struct *work)
{
struct mlx5_cmd_work_ent *ent = container_of(work, struct mlx5_cmd_work_ent, work);
@@ -923,7 +904,7 @@ static void cmd_work_handler(struct work
sem = ent->page_queue ? &cmd->pages_sem : &cmd->sem;
down(sem);
if (!ent->page_queue) {
- alloc_ret = cmd_alloc_index_retry(cmd);
+ alloc_ret = cmd_alloc_index(cmd);
if (alloc_ret < 0) {
mlx5_core_err(dev, "failed to allocate command entry\n");
if (ent->callback) {