Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753996AbbH0NWr (ORCPT ); Thu, 27 Aug 2015 09:22:47 -0400 Received: from mail-wi0-f177.google.com ([209.85.212.177]:36554 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752774AbbH0NWq (ORCPT ); Thu, 27 Aug 2015 09:22:46 -0400 MIME-Version: 1.0 In-Reply-To: References: <1439537446-7713-1-git-send-email-sdliyong@gmail.com> Date: Thu, 27 Aug 2015 15:22:44 +0200 Message-ID: Subject: Re: [PATCH] mmc: block: disable the reliable write If the card does not support CMD23 From: Ulf Hansson To: Yong Li Cc: Chris Ball , linux-mmc , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1783 Lines: 47 On 25 August 2015 at 14:06, Ulf Hansson wrote: > On 14 August 2015 at 09:30, wrote: >> From: Yong Li >> >> Signed-off-by: Yong Li >> --- >> 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); > > Further down in mmc_blk_rw_rq_prep() we check for > MMC_QUIRK_BLK_NO_CMD23. That check becomes redundant after this > change, please remove that check as a part of this patch as well. > >> >> memset(brq, 0, sizeof(struct mmc_blk_request)); >> brq->mrq.cmd = &brq->cmd; >> -- >> 2.1.0 >> > Please ignore my previous answer. MMC_QUIRK_BLK_NO_CMD23 is intended to indicate to the mmc block layer whether using CMD23 for regular block IO request could have a performance impact for some cards. If that's the case we don't use it - except when using reliable write! So this patch is just plain wrong. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/