public inbox for linux-mmc@vger.kernel.org
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: "Nath, Arindam" <Arindam.Nath@amd.com>
Cc: zhangfei gao <zhangfei.gao@gmail.com>,
	"cjb@laptop.org" <cjb@laptop.org>,
	"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	"Su, Henry" <Henry.Su@amd.com>, "Lu, Aaron" <Aaron.Lu@amd.com>,
	"anath.amd@gmail.com" <anath.amd@gmail.com>
Subject: Re: [PATCH 01/12] mmc: sdhci: add support for auto CMD23
Date: Fri, 18 Feb 2011 14:08:35 +0100	[thread overview]
Message-ID: <201102181408.35946.arnd@arndb.de> (raw)
In-Reply-To: <6C03668EAF45B747AF947A1603D1B300DCED1913@SAUSEXMBP01.amd.com>

On Friday 18 February 2011, Nath, Arindam wrote:
> > AFAICT, whether CMD23 can be used or not is primarily a decision based
> > on
> > the card, and the block driver might want issue it for a longer range
> > if it needs to split a block request into multiple MMC requests.
> 
> Thanks for the comments. Yes, whether a card supports CMD23 depends on
> the card, but Auto CMD23 is a feature added to the Host Controller v3.00
> just like Auto CMD12. I am already doing a check inside 
> sdhci_host_auto_cmd23_supported() whether the card supports CMD23, and
> whether the request is for multiple block transfers. Also I tried to make
> my implementation consistent with Auto CMD12 implementation already
> there in the sdhc code.

Ok, I see.

But, assuming that the block driver was changed to always to CMD23 where
appropriate, what is the advantage auf Auto CMD23?

As far as I can tell, changing the block driver would make all hosts
faster, not just sdhci, and it would be able to cover the split requests
I mentioned.

	Arnd


  reply	other threads:[~2011-02-18 13:23 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-15  9:34 [PATCH 00/12] add support for sd host controller v3.00 Arindam Nath
2011-02-15  9:34 ` [PATCH 01/12] mmc: sdhci: add support for auto CMD23 Arindam Nath
2011-02-15 20:58   ` Nicolas Pitre
2011-02-16  8:04     ` Nath, Arindam
2011-02-18 10:45   ` zhangfei gao
2011-02-18 10:50     ` Arnd Bergmann
2011-02-18 12:08       ` Nath, Arindam
2011-02-18 13:08         ` Arnd Bergmann [this message]
2011-02-18 13:35           ` Nath, Arindam
2011-02-18 15:40             ` Arnd Bergmann
2011-02-18 15:49               ` [PATCH 01/12] mmc: sdhci: add support for SD Host Controller 3.0 Philip Rakity
2011-02-18 17:17                 ` Nath, Arindam
2011-02-18 18:55                   ` Nicolas Pitre
2011-02-18 19:08                     ` Philip Rakity
2011-02-18 19:06                   ` Philip Rakity
2011-02-18 11:53     ` [PATCH 01/12] mmc: sdhci: add support for auto CMD23 Nath, Arindam
2011-02-15  9:35 ` [PATCH 02/12] mmc: sd: add support for signal voltage switch procedure Arindam Nath
2011-02-15 10:16   ` Wolfram Sang
2011-02-16  7:55     ` Nath, Arindam
2011-02-15 21:18   ` Nicolas Pitre
2011-02-16  8:08     ` Nath, Arindam
2011-03-01 16:02   ` subhashj
2011-03-02  8:06     ` Nath, Arindam
2011-03-03 13:16       ` subhashj
2011-03-03 13:34         ` Nath, Arindam
2011-03-03 21:08           ` subhashj
2011-03-03 22:49             ` Philip Rakity
2011-03-04  6:10               ` Nath, Arindam
2011-02-15  9:35 ` [PATCH 03/12] mmc: sd: query function modes for uhs cards Arindam Nath
2011-02-15  9:35 ` [PATCH 04/12] mmc: sd: add support for driver type selection Arindam Nath
2011-02-15  9:35 ` [PATCH 05/12] mmc: sdhci: reset sdclk before setting high speed enable Arindam Nath
2011-02-15  9:35 ` [PATCH 06/12] mmc: sd: add support for uhs bus speed mode selection Arindam Nath
2011-03-09 21:43   ` Philip Rakity
2011-02-15  9:35 ` [PATCH 07/12] mmc: sd: set current limit for uhs cards Arindam Nath
2011-02-15  9:35 ` [PATCH 08/12] mmc: sd: report correct speed and capacity of " Arindam Nath
2011-02-15  9:35 ` [PATCH 09/12] mmc: sd: add support for tuning during uhs initialization Arindam Nath
2011-02-18 10:50   ` zhangfei gao
2011-02-18 11:33     ` Nath, Arindam
2011-02-15  9:35 ` [PATCH 10/12] mmc: sdhci: enable preset value after " Arindam Nath
2011-02-15  9:35 ` [PATCH 11/12] mmc: sdhci: add support for programmable clock mode Arindam Nath
2011-02-15  9:35 ` [PATCH 12/12] mmc: sdhci: add support for retuning mode 1 Arindam Nath
2011-02-15 19:43 ` [PATCH 00/12] add support for sd host controller v3.00 Chris Ball
2011-02-16  8:00   ` Nath, Arindam
2011-02-16 20:55 ` Chris Ball
2011-02-17  2:03   ` Nath, Arindam

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=201102181408.35946.arnd@arndb.de \
    --to=arnd@arndb.de \
    --cc=Aaron.Lu@amd.com \
    --cc=Arindam.Nath@amd.com \
    --cc=Henry.Su@amd.com \
    --cc=anath.amd@gmail.com \
    --cc=cjb@laptop.org \
    --cc=linux-mmc@vger.kernel.org \
    --cc=zhangfei.gao@gmail.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