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From: Ulf Hansson <>
To: "Y.b. Lu" <>
Cc: Adrian Hunter <>,
	"" <>,
	Sachin Miglani <>
Subject: Re: [PATCH] mmc: sdhci: fix up CMD12 sending
Date: Thu, 16 Jan 2020 16:36:35 +0100
Message-ID: <> (raw)
In-Reply-To: <>

On Wed, 8 Jan 2020 at 10:37, Y.b. Lu <> wrote:
> Hi Uffe and Adrian,
> Back again on this topic. Actually we are trying to make the error recovery work after data error of CMD18 in linux-4.14.
> With this patch, when CMD18 data error got, manual CMD12 would be sent. And then went into mmc_blk_cmd_recovery(). (Should be mmc_blk_mq_rw_recovery() in latest linux-5.5-rc2.)
> In mmc_blk_cmd_recovery(), re-tuning would fail before sending CMD13 on our specific board.
> This may be some issue related to specific eMMC card we are investigating.
> The above is just background introduction, and you may not care about that:)
> I'd like to have some queries on CMD12 usage in MMC driver.
> 1. It seems CMD12 is always not using ABORT type for sending in sdhci.c. The SDHCI_CMD_ABORTCMD hasn't been used. Is this issue?

I defer that question to Adrian.

> 2. In block.c, CMD12 uses R1 response for data reading and R1B response for writing. Is it ok to use R1 response for SD? The SD spec mentions only R1B response for CMD12.

I think the specs isn't that clear on this. In this case, the R1B, is
an R1 with an *optional* busy signaling on DAT0, unless it has been
changed lately.

Additionally, as far as can tell, there have been no reports about
problems with the current approach for "reads". Are you saying there


Kind regards

  reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <>
2019-11-29  9:17 ` Adrian Hunter
2019-12-10  9:51 ` Ulf Hansson
2020-01-08  9:37   ` Y.b. Lu
2020-01-16 15:36     ` Ulf Hansson [this message]
2020-01-17 14:15       ` Adrian Hunter

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