From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756926Ab1F1Jkf (ORCPT ); Tue, 28 Jun 2011 05:40:35 -0400 Received: from mail-qw0-f46.google.com ([209.85.216.46]:37551 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756749Ab1F1Jjn convert rfc822-to-8bit (ORCPT ); Tue, 28 Jun 2011 05:39:43 -0400 MIME-Version: 1.0 In-Reply-To: <1309248717-14606-13-git-send-email-per.forlin@linaro.org> References: <1309248717-14606-1-git-send-email-per.forlin@linaro.org> <1309248717-14606-13-git-send-email-per.forlin@linaro.org> Date: Tue, 28 Jun 2011 11:39:41 +0200 Message-ID: Subject: Re: [PATCH v8 12/12] mmc: block: add handling for two parallel block requests in issue_rw_rq From: Per Forlin To: linaro-dev@lists.linaro.org, Nicolas Pitre , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, Nickolay Nickolaev , Venkatraman S , Linus Walleij Cc: Chris Ball , Per Forlin Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28 June 2011 10:11, Per Forlin wrote: > Change mmc_blk_issue_rw_rq() to become asynchronous. > The execution flow looks like this: > The mmc-queue calls issue_rw_rq(), which sends the request > to the host and returns back to the mmc-queue. The mmc-queue calls > issue_rw_rq() again with a new request. This new request is prepared, > in isuue_rw_rq(), then it waits for the active request to complete before > pushing it to the host. When to mmc-queue is empty it will call > isuue_rw_rq() with req=NULL to finish off the active request > without starting a new request. > > Signed-off-by: Per Forlin > --- >  drivers/mmc/card/block.c |   80 +++++++++++++++++++++++++++++++++++++-------- >  drivers/mmc/card/queue.c |   17 +++++++--- >  drivers/mmc/card/queue.h |    1 + >  3 files changed, 78 insertions(+), 20 deletions(-) > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index 7ed2c68..825741e 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c ... > @@ -1066,6 +1085,13 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req) >                        ret = __blk_end_request(req, 0, >                                                brq->data.bytes_xfered); >                        spin_unlock_irq(&md->lock); > +                       if (status == MMC_BLK_SUCCESS && ret) { > +                               /* If this happen it is a bug */ > +                               printk(KERN_ERR "%s BUG rq_tot %d d_xfer %d\n", > +                                      __func__, blk_rq_bytes(req), > +                                      brq->data.bytes_xfered); + rqc = NULL If there is a new request (rqc != NULL) it will already be started when reaching this point. If rqc is set it will be started again at start_new_req. I wonder if this paranoia check is necessary. If "status == MMC_BLK_SUCCESS" all bytes are transferred and no error returned from mmc layer. __blk_end_request would always return 0 in this case, please comment if you disagree. ... > + start_new_req: > +       if (rqc) { > +               mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq); > +               mmc_start_req(card->host, &mq->mqrq_cur->mmc_active, NULL); > +       } > + >        return 0; >  } /Per