Re: [PATCH v10 16/18] scsi: ufs: Simplify ufshcd_auto_hibern8_update()

Can Guo
2023-08-21T05:36:06Z

On 8/19/2023 3:34 AM, Bart Van Assche wrote:
> 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. This patch makes the next patch in this
> series easier to read.
>
> Cc: Martin K. Petersen <martin.petersen@oracle.com>
> Cc: Can Guo <quic_cang@quicinc.com>
> Cc: Avri Altman <avri.altman@wdc.com>
> Cc: Bao D. Nguyen <quic_nguyenb@quicinc.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
> drivers/ufs/core/ufshcd.c | 16 ++++------------
> 1 file changed, 4 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index a08924972b20..68bf8e94eee6 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -4347,21 +4347,13 @@ static void ufshcd_configure_auto_hibern8(struct ufs_hba *hba)
>
> int 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 0;
>
> - 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);

Reviewed-by: Can Guo <quic_cang@quicinc.com>