From: Jaegeuk Kim <jaegeuk@kernel.org>
To: Eric Biggers <ebiggers@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
"Martin K . Petersen" <martin.petersen@oracle.com>,
Bart Van Assche <bvanassche@acm.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Asutosh Das <asutoshd@codeaurora.org>,
Avri Altman <avri.altman@wdc.com>, Bean Huo <beanhuo@micron.com>,
Stanley Chu <stanley.chu@mediatek.com>,
Can Guo <cang@codeaurora.org>
Subject: Re: [PATCH] scsi: ufs: add a quirk to disable FUA support
Date: Tue, 31 May 2022 13:53:33 -0700 [thread overview]
Message-ID: <YpaATWTiipNERoVF@google.com> (raw)
In-Reply-To: <YpZ71MU7+DRedq5S@gmail.com>
On 05/31, Eric Biggers wrote:
> On Tue, May 31, 2022 at 01:10:53PM -0700, Jaegeuk Kim wrote:
> > UFS stack shows very low performance of FUA comparing to write and cache_flush.
> > Let's add a quirk to adjust it.
> >
> > E.g., average latency according to the chunk size of write
> >
> > Write(us/KB) 4 64 256 1024 2048
> > FUA 873.792 754.604 995.624 1011.67 1067.99
> > CACHE_FLUSH 824.703 712.98 800.307 1019.5 1037.37
> >
> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> > ---
> > drivers/scsi/ufs/ufshcd.c | 3 +++
> > drivers/scsi/ufs/ufshcd.h | 5 +++++
> > 2 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 3f9caafa91bf..811f3467879c 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -5035,6 +5035,9 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
> > */
> > sdev->silence_suspend = 1;
> >
> > + if (hba->quirks & UFSHCD_QUIRK_BROKEN_FUA)
> > + sdev->broken_fua = 1;
> > +
> > ufshcd_crypto_register(hba, q);
> >
> > return 0;
> > diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> > index 94f545be183a..6c480c6741d6 100644
> > --- a/drivers/scsi/ufs/ufshcd.h
> > +++ b/drivers/scsi/ufs/ufshcd.h
> > @@ -602,6 +602,11 @@ enum ufshcd_quirks {
> > * support physical host configuration.
> > */
> > UFSHCD_QUIRK_SKIP_PH_CONFIGURATION = 1 << 16,
> > +
> > + /*
> > + * This quirk disables FUA support.
> > + */
> > + UFSHCD_QUIRK_BROKEN_FUA = 1 << 17,
> > };
>
> "Broken" is ambiguous. IIUC, the issue is that FUA performance is very bad, not
> that it doesn't work. Can you clarify the intent in the comment?
My intent is FUA was supposed to be better than write+cache_flush.
>
> Also, this patch does nothing by itself. Which UFS host driver(s) need this
> quirk bit? Can you update them to use it? Or do they all need this, in which
> case a quirk bit would be unnecessary?
Likewise other quick bits, using this is up to SoC or UFS vendors. I
think that combination is up to OEMs who is building the product.
>
> - Eric
next prev parent reply other threads:[~2022-05-31 20:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-31 20:10 [PATCH] scsi: ufs: add a quirk to disable FUA support Jaegeuk Kim
2022-05-31 20:34 ` Eric Biggers
2022-05-31 20:53 ` Jaegeuk Kim [this message]
2022-05-31 21:25 ` Eric Biggers
2022-06-07 16:45 ` Asutosh Das
2022-06-01 5:24 ` Adrian Hunter
2022-06-01 11:59 ` Bart Van Assche
2022-06-01 17:06 ` Jaegeuk Kim
2022-06-01 17:05 ` Jaegeuk Kim
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=YpaATWTiipNERoVF@google.com \
--to=jaegeuk@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=asutoshd@codeaurora.org \
--cc=avri.altman@wdc.com \
--cc=beanhuo@micron.com \
--cc=bvanassche@acm.org \
--cc=cang@codeaurora.org \
--cc=ebiggers@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.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).