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From: Nicolas Pitre <nico@fluxnic.net>
To: Bing Zhao <bzhao@marvell.com>
Cc: linux-mmc@vger.kernel.org, Michal Miroslaw <mirqus@gmail.com>,
	Chris Ball <cjb@laptop.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2] sdio: skip initialization on powered resume
Date: Thu, 02 Sep 2010 13:54:11 -0400 (EDT)	[thread overview]
Message-ID: <alpine.LFD.2.00.1009021344430.19366@xanadu.home> (raw)
In-Reply-To: <1283391692-14150-1-git-send-email-bzhao@marvell.com>

On Wed, 1 Sep 2010, Bing Zhao wrote:

> Quoted Michal Miroslaw's comment:
> 
> Simplified SDIO spec v.2.00 (section 6.14 - Bus State Diagram)
> suggests, that initialization commands (CMD5, CMD3) are not accepted
> in CMD state. As the card stays in that state on powered suspend (no
> resetting CMD52 nor power cycle is issued) then reinitialization
> should be entirely skipped on resume unless the power was lost between
> suspend and resume (or card was temporarily removed from the slot).
> 
> Signed-off-by: Bing Zhao <bzhao@marvell.com>

Comments below.

> +	/*
> +	 * Simplified SDIO spec v2.00 (section 6.14 - Bus State Diagram)
> +	 * suggests that initialization should be skipped on powered resume.
> +	 */
> +	if (!(host->pm_flags & MMC_PM_KEEP_POWER)) {
> +		err = mmc_sdio_init_card(host, host->ocr, host->card,
> +					host->pm_flags & MMC_PM_KEEP_POWER);
> +	}

Please look at the if() condition, and at the last argument to 
mmc_sdio_init_card(), then ponder.

I think the proper fix goes _inside_ mmc_sdio_init_card() as there are 
certainly still validation checks which are appropriate to perform.


Nicolas

  reply	other threads:[~2010-09-02 17:54 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-02  1:41 [PATCH v2] sdio: skip initialization on powered resume Bing Zhao
2010-09-02 17:54 ` Nicolas Pitre [this message]
2010-09-02 22:58   ` Bing Zhao
2010-09-02 23:30     ` Nicolas Pitre
2010-09-08  1:03       ` Bing Zhao
2010-09-08  1:28         ` Nicolas Pitre
2010-09-08  2:10           ` Bing Zhao
2010-09-14 10:15             ` Sahitya Tummala
2010-09-16  0:27               ` Bing Zhao
2010-09-16  2:26                 ` Nicolas Pitre
2011-01-21  9:07                   ` zhangfei gao
2011-01-22  2:22                     ` Bing Zhao
2011-01-22  2:55                       ` Nicolas Pitre
2011-01-22  3:27                         ` Bing Zhao
2011-01-22  3:38                           ` Chris Ball
2011-01-22 22:01                     ` Ohad Ben-Cohen
2011-01-25  2:17                       ` Bing Zhao
2011-01-25  3:10                         ` zhangfei gao
2011-01-25  7:11                           ` Ohad Ben-Cohen
2011-01-25  7:24                             ` Ohad Ben-Cohen

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