linux-kernel - Re: [PATCH] mmc: block: disable the reliable write If the card does not support CMD23

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Message-ID: <55CDA30E.7030208@rock-chips.com>
Date:	Fri, 14 Aug 2015 16:13:02 +0800
From:	Shawn Lin <shawn.lin@...k-chips.com>
To:	sdliyong@...il.com, chris@...ntf.net, ulf.hansson@...aro.org,
	linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	shawn.lin@...k-chips.com
Subject: Re: [PATCH] mmc: block: disable the reliable write If the card does
 not support CMD23

在 2015/8/14 15:30, sdliyong@...il.com 写道:
> From: Yong Li <sdliyong@...il.com>
>
> Signed-off-by: Yong Li <sdliyong@...il.com>
> ---
>   drivers/mmc/card/block.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 452782b..d9e3c45 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1366,7 +1366,8 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
>   	bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
>   			  (req->cmd_flags & REQ_META)) &&
>   		(rq_data_dir(req) == WRITE) &&
> -		(md->flags & MMC_BLK_REL_WR);
> +		(md->flags & MMC_BLK_REL_WR) &&
> +		!(card->quirks & MMC_QUIRK_BLK_NO_CMD23);

Hi Yong,

pls check that code below.

MMC_BLK_REL_WR will not be enabled if we know this card CANNOT support 
CMD23 form SCR. AND， "card->quirks & MMC_QUIRK_BLK_NO_CMD23" would be 
checked here as well. So I think your code is unnecessary.

if ((md->flags & MMC_BLK_CMD23) && mmc_op_multi(brq->cmd.opcode) &&
	    (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23) ||
	     do_data_tag)) {
		brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
		brq->sbc.arg = brq->data.blocks |
			(do_rel_wr ? (1 << 31) : 0) |
			(do_data_tag ? (1 << 29) : 0);
		brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
		brq->mrq.sbc = &brq->sbc;
	}

Thanks.
Shawn

>
>   	memset(brq, 0, sizeof(struct mmc_blk_request));
>   	brq->mrq.cmd = &brq->cmd;
>


-- 
Shawn Lin

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