lkml.org 
[lkml]   [2019]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v1 2/2] scsi: ufs: disable interrupt during clock-gating
From
Date
On 12/7/2019 4:22 AM, Stanley Chu wrote:
> Similar to suspend, ufshcd interrupt can be disabled since
> there won't be any host controller transaction expected till
> clocks ungated.
>
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
> ---
> drivers/scsi/ufs/ufshcd.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index f80bd4e811cb..5de105e82c32 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1490,6 +1490,8 @@ static void ufshcd_ungate_work(struct work_struct *work)
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> ufshcd_setup_clocks(hba, true);
>
> + ufshcd_enable_irq(hba);
> +
> /* Exit from hibern8 */
> if (ufshcd_can_hibern8_during_gating(hba)) {
> /* Prevent gating in this path */
> @@ -1636,6 +1638,8 @@ static void ufshcd_gate_work(struct work_struct *work)
> ufshcd_set_link_hibern8(hba);
> }
>
> + ufshcd_disable_irq(hba);
> +
> if (!ufshcd_is_link_active(hba))
> ufshcd_setup_clocks(hba, false);
> else
>

Hi,
Does this save significant power? I see that gate/ungate of clocks
happen far too frequently than suspend/resume.

Have you considered how much latency this would add to the
gating/ungating path?

-asd

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

\
 
 \ /
  Last update: 2019-12-18 00:26    [W:0.079 / U:13.360 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site