From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754134AbeDPKv2 (ORCPT ); Mon, 16 Apr 2018 06:51:28 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:58046 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753359AbeDPKv0 (ORCPT ); Mon, 16 Apr 2018 06:51:26 -0400 Subject: Re: [PATCH 08/12] mmc: reduce use of block bounce buffers To: Christoph Hellwig , iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org References: <20180416085032.7367-1-hch@lst.de> <20180416085032.7367-9-hch@lst.de> From: Robin Murphy Message-ID: <2067b808-65b3-e4d9-e376-1062abc1542f@arm.com> Date: Mon, 16 Apr 2018 11:51:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180416085032.7367-9-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/04/18 09:50, Christoph Hellwig wrote: > We can rely on the dma-mapping code to handle any DMA limits that is > bigger than the ISA DMA mask for us (either using an iommu or swiotlb), > so remove setting the block layer bounce limit for anything but bouncing > for highmem pages. > > Signed-off-by: Christoph Hellwig > --- > drivers/mmc/core/queue.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c > index 56e9a803db21..60a02a763d01 100644 > --- a/drivers/mmc/core/queue.c > +++ b/drivers/mmc/core/queue.c > @@ -351,17 +351,14 @@ static const struct blk_mq_ops mmc_mq_ops = { > static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) > { > struct mmc_host *host = card->host; > - u64 limit = BLK_BOUNCE_HIGH; > - > - if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) > - limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT; > > blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue); > blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue); > if (mmc_can_erase(card)) > mmc_queue_setup_discard(mq->queue, card); > > - blk_queue_bounce_limit(mq->queue, limit); > + if (!mmc_dev(host)->dma_mask || !mmc_dev(host)->dma_mask) I'm almost surprised that GCC doesn't warn about "x || x", but nevertheless I think you've lost a "*" here... Robin. > + blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH); > blk_queue_max_hw_sectors(mq->queue, > min(host->max_blk_count, host->max_req_size / 512)); > blk_queue_max_segments(mq->queue, host->max_segs); >