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

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Message-ID: <BLU168-W190F53E1D56BC43511D7BFD67B0@phx.gbl>
Date:	Sat, 15 Aug 2015 20:14:05 +0800
From:	LIYONG <sdliyong@...il.com>
To:	Shawn Lin <shawn.lin@...k-chips.com>,
	"chris@...ntf.net" <chris@...ntf.net>,
	"ulf.hansson@...aro.org" <ulf.hansson@...aro.org>,
	"linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] mmc: block: disable the reliable write If the card does
 not support CMD23

Thanks Shawn. Please help to check the below in the mmc_blk_rw_rq_prep:
	if (do_rel_wr)
		mmc_apply_rel_rw(brq, card, req);

I think we need to set the do_rel_wr to false( at the beginning of this function) if the card does not support the CMD23. The above code is executed before the "if ((md->flags & MMC_BLK_CMD23)" code.

Thanks,
Yong Li
----------------------------------------
> Subject: Re: [PATCH] mmc: block: disable the reliable write If the card does not support CMD23
> 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
> From: shawn.lin@...k-chips.com
> Date: Fri, 14 Aug 2015 16:13:02 +0800
>
> 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
>