linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Can Guo <cang@codeaurora.org>
To: Stanley Chu <stanley.chu@mediatek.com>
Cc: linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
	avri.altman@wdc.com, alim.akhtar@samsung.com, jejb@linux.ibm.com,
	beanhuo@micron.com, asutoshd@codeaurora.org,
	matthias.bgg@gmail.com, bvanassche@acm.org,
	linux-mediatek@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, kuohong.wang@mediatek.com,
	peter.wang@mediatek.com, chun-hung.wu@mediatek.com,
	andy.teng@mediatek.com
Subject: Re: [PATCH v1 1/2] scsi: ufs: add required delay after gating reference clock
Date: Mon, 17 Feb 2020 21:22:49 +0800	[thread overview]
Message-ID: <e518c4d1d94ec15e9c4c31c34a9e42d1@codeaurora.org> (raw)
In-Reply-To: <1581945168.26304.4.camel@mtksdccf07>

On 2020-02-17 21:12, Stanley Chu wrote:
> Hi Can,
> 
> 
>> >  			} else if (!on && clki->enabled) {
>> >  				clk_disable_unprepare(clki->clk);
>> > +				wait_us = hba->dev_info.clk_gating_wait_us;
>> > +				if (ref_clk && wait_us)
>> > +					usleep_range(wait_us, wait_us + 10);
>> 
>> Hi St,anley,
>> 
>> If wait_us is 1us, it would be inappropriate to use usleep_range() 
>> here.
>> You have checks of the delay in patch #2, but why it is not needed 
>> here?
>> 
>> Thanks,
>> Can Guo.
> 
> You are right. I could make that delay checking as common function so 
> it
> can be used here as well to cover all possible values.
> 
> Thanks for suggestion.
> Stanley

Hi Stanley,

One more thing, as in patch #2, you have already added delays in your
ufshcd_vops_setup_clocks(OFF, PRE_CHANGE) path, plus this delay here,
don't you delay for 2*bRefClkGatingWaitTime in ufshcd_setup_clocks()?
As the delay added in your vops also delays the actions of turning
off all the other clocks in ufshcd_setup_clocks(), you don't need the
delay here again, do you agree?

Thanks,
Can Guo.

  reply	other threads:[~2020-02-17 13:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-17  9:35 [PATCH v1 0/2] scsi: ufs: fix waiting time for reference clock Stanley Chu
2020-02-17  9:35 ` [PATCH v1 1/2] scsi: ufs: add required delay after gating " Stanley Chu
2020-02-17 12:58   ` Can Guo
2020-02-17 13:12     ` Stanley Chu
2020-02-17 13:22       ` Can Guo [this message]
2020-02-17 13:34         ` Stanley Chu
2020-02-17 13:42           ` Can Guo
2020-02-19  2:35             ` Can Guo
2020-02-19  9:11               ` Stanley Chu
2020-02-19 10:33                 ` Can Guo
2020-02-20 13:30                   ` Stanley Chu
2020-02-17 16:17   ` Bart Van Assche
2020-02-18  0:50     ` Stanley Chu
2020-02-17  9:35 ` [PATCH v1 2/2] scsi: ufs: ufs-mediatek: add waiting time for " Stanley Chu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=e518c4d1d94ec15e9c4c31c34a9e42d1@codeaurora.org \
    --to=cang@codeaurora.org \
    --cc=alim.akhtar@samsung.com \
    --cc=andy.teng@mediatek.com \
    --cc=asutoshd@codeaurora.org \
    --cc=avri.altman@wdc.com \
    --cc=beanhuo@micron.com \
    --cc=bvanassche@acm.org \
    --cc=chun-hung.wu@mediatek.com \
    --cc=jejb@linux.ibm.com \
    --cc=kuohong.wang@mediatek.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=matthias.bgg@gmail.com \
    --cc=peter.wang@mediatek.com \
    --cc=stanley.chu@mediatek.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).