scsi: ufs: core: Simplify ufshcd_auto_hibern8_update()

Calls to ufshcd_auto_hibern8_update() are already serialized: this function
is either called if user space software is not running (preparing to
suspend) or from a single sysfs store callback function.  Kernfs serializes
sysfs .store() callbacks. No functionality is changed.

Reviewed-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Reviewed-by: Can Guo <quic_cang@quicinc.com>
Cc: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20231214192416.3638077-3-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 608dba5..d6ae5d1 100644 (file)
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -4423,21 +4423,13 @@ static void ufshcd_configure_auto_hibern8(struct ufs_hba *hba)
 
 void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
 {
-       unsigned long flags;
-       bool update = false;
+       const u32 cur_ahit = READ_ONCE(hba->ahit);
 
-       if (!ufshcd_is_auto_hibern8_supported(hba))
+       if (!ufshcd_is_auto_hibern8_supported(hba) || cur_ahit == ahit)
                return;
 
-       spin_lock_irqsave(hba->host->host_lock, flags);
-       if (hba->ahit != ahit) {
-               hba->ahit = ahit;
-               update = true;
-       }
-       spin_unlock_irqrestore(hba->host->host_lock, flags);
-
-       if (update &&
-           !pm_runtime_suspended(&hba->ufs_device_wlun->sdev_gendev)) {
+       WRITE_ONCE(hba->ahit, ahit);
+       if (!pm_runtime_suspended(&hba->ufs_device_wlun->sdev_gendev)) {
                ufshcd_rpm_get_sync(hba);
                ufshcd_hold(hba);
                ufshcd_configure_auto_hibern8(hba);