netdev - [PATCH net-next 2/9] iavf: simplify mutex

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Date: Mon, 23 Oct 2023 16:08:19 -0700
From: Jacob Keller <jacob.e.keller@...el.com>
To: netdev@...r.kernel.org,
	David Miller <davem@...emloft.net>,
	Jakub Kicinski <kuba@...nel.org>
Cc: Michal Schmidt <mschmidt@...hat.com>,
	Wojciech Drewek <wojciech.drewek@...el.com>,
	Rafal Romanowski <rafal.romanowski@...el.com>,
	Jacob Keller <jacob.e.keller@...el.com>
Subject: [PATCH net-next 2/9] iavf: simplify mutex_trylock+sleep loops

From: Michal Schmidt <mschmidt@...hat.com>

This pattern appears in two places in the iavf source code:
  while (!mutex_trylock(...))
      usleep_range(...);

That's just mutex_lock with extra steps.
The pattern is a leftover from when iavf used bit flags instead of
mutexes for locking. Commit 5ac49f3c2702 ("iavf: use mutexes for locking
of critical sections") replaced test_and_set_bit with !mutex_trylock,
preserving the pattern.

Simplify it to mutex_lock.

Signed-off-by: Michal Schmidt <mschmidt@...hat.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@...el.com>
Tested-by: Rafal Romanowski <rafal.romanowski@...el.com>
Signed-off-by: Jacob Keller <jacob.e.keller@...el.com>
---
 drivers/net/ethernet/intel/iavf/iavf_main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 8bfa928ab415..da9cd53afc24 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -3011,8 +3011,7 @@ static void iavf_reset_task(struct work_struct *work)
 		return;
 	}
 
-	while (!mutex_trylock(&adapter->client_lock))
-		usleep_range(500, 1000);
+	mutex_lock(&adapter->client_lock);
 	if (CLIENT_ENABLED(adapter)) {
 		adapter->flags &= ~(IAVF_FLAG_CLIENT_NEEDS_OPEN |
 				    IAVF_FLAG_CLIENT_NEEDS_CLOSE |
@@ -5064,8 +5063,7 @@ static int __maybe_unused iavf_suspend(struct device *dev_d)
 
 	netif_device_detach(netdev);
 
-	while (!mutex_trylock(&adapter->crit_lock))
-		usleep_range(500, 1000);
+	mutex_lock(&adapter->crit_lock);
 
 	if (netif_running(netdev)) {
 		rtnl_lock();
-- 
2.41.0