public inbox for linux-mmc@vger.kernel.org
 help / color / mirror / Atom feed
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH 1/2] mmc: core: when downgrading HS400, callback into drivers earlier
Date: Mon, 8 Jun 2020 22:41:14 +0200	[thread overview]
Message-ID: <20200608204113.GC917@ninjato> (raw)
In-Reply-To: <TY2PR01MB369228A84C46D582D1219EFFD8850@TY2PR01MB3692.jpnprd01.prod.outlook.com>

[-- Attachment #1: Type: text/plain, Size: 1227 bytes --]

Hi Shimoda-san,

thank you very much for the review!

> > The driver specific downgrade function makes more sense if we run it
> > before we switch anything, not after we already switched. Otherwise some
> > non-HS400 communication has already happened.
> > 
> > No need to convert users. There is only one currenty which needs this
> > change in a later patchset.
> 
> Perhaps, should we add Fixes tag like below?
> 
> Fixes: ba6c7ac3a2f4 ("mmc: core: more fine-grained hooks for HS400 tuning")

I am not sure. While it is more correct to move the call to
hs400_downgrade upwards, it does not really fix a bug on its own.
Without patch 2/2 of this series, there is not really a huge difference
when we disable the SCC the old way. For the new way, this patch is a
prerequisite.


> > +	/* Prepare host to downgrade to HS timing */
> > +	if (host->ops->hs400_downgrade)
> > +		host->ops->hs400_downgrade(host);
> > +
> 
> IICU, we should call hs400_downgrade() between the __mmc_switch("EXT_CSD_TIMING_HS")
> and mmc_set_timing(card->host, MMC_TIMING_MMC_HS) because the switch command should
> be issued in HS400 mode.

Yes, of course, you are right. Will fix!

Kind regards,

   Wolfram


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  reply	other threads:[~2020-06-08 20:41 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-04 11:20 [PATCH 0/2] renesas_sdhi: fix hang when SCC loses its clock Wolfram Sang
2020-06-04 11:20 ` [PATCH 1/2] mmc: core: when downgrading HS400, callback into drivers earlier Wolfram Sang
2020-06-08  6:02   ` Yoshihiro Shimoda
2020-06-08 20:41     ` Wolfram Sang [this message]
2020-06-09 10:35       ` Yoshihiro Shimoda
2020-06-04 11:20 ` [PATCH 2/2] mmc: renesas_sdhi: keep SCC clock active when tuning Wolfram Sang
2020-06-08  6:35   ` Yoshihiro Shimoda
2020-06-08 21:27     ` Wolfram Sang
2020-06-09 10:41       ` Yoshihiro Shimoda
2020-08-14  7:15         ` Wolfram Sang
2020-08-28  0:51           ` Yoshihiro Shimoda
2020-09-01 10:24             ` Wolfram Sang
2020-09-01 13:39               ` Wolfram Sang

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=20200608204113.GC917@ninjato \
    --to=wsa+renesas@sang-engineering.com \
    --cc=linux-mmc@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=yoshihiro.shimoda.uh@renesas.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