From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 23DD9156C40; Thu, 26 Sep 2024 15:56:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727366187; cv=none; b=aPZ8pBkkfbP1DvcRrGQDrMD7SbV1qpwcs+DoIvTOaTpw6rdcqrPlRolYBHMCeIr1Tj8MF2aiXFk2OwFli8UahKHcBGk2fiKz1WqOsomMc3WfLSsVgvjnX+00aj91wDCv4FYRx3gbaNf46md5q8k2pL+OrPmT9XuGNigKNRfBErk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727366187; c=relaxed/simple; bh=WBnnx5zlorm4kEs0yeAw44dctNIiEVNABaauurFcP0U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UNHRQYEUJ6d8/BfiRwFsFzydWNfnqe3Kt/DH8VvfNOAOqUkuODJTULJ4lUHZcwTUiHl+Z5Gf0cIHm+6a7nQ13hxwp4dsLbaPUENWc6SFTJXg61qZ0P90YfRj+7EuIpA2jaspGQW/MB0tZIuh77foVgawOwCHlC9AWHW3PhOUYN4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7924D14BF; Thu, 26 Sep 2024 08:56:47 -0700 (PDT) Received: from [10.1.196.40] (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BE13E3F587; Thu, 26 Sep 2024 08:56:16 -0700 (PDT) Message-ID: Date: Thu, 26 Sep 2024 16:56:15 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mmc: core: Only set maximum DMA segment size if DMA is supported To: Guenter Roeck , Ulf Hansson Cc: Paul Walmsley , Samuel Holland , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Christoph Hellwig References: <20240924210123.2288529-1-linux@roeck-us.net> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20240924210123.2288529-1-linux@roeck-us.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 24/09/2024 10:01 pm, Guenter Roeck wrote: > Since upstream commit 334304ac2bac ("dma-mapping: don't return errors > from dma_set_max_seg_size") calling dma_set_max_seg_size() on a device > not supporting DMA results in a warning traceback. This is seen when > booting the sifive_u machine from SD. The underlying SPI controller > (sifive,spi0 compatible) explicitly sets dma_mask to NULL. Hmm, that driver probably shouldn't be doing that, but either way it's not actually relevant to this check - what's significant is that when the MMC host device is an "mmc-spi-slot" instance, its mmc_dev() ends up being the SPI *device* itself, not the grandparent SPI controller. Thus the patch itself is appropriate on the basis that MMC hosts may exist on non-DMA-capable buses, so the subsystem needs to consider that. Reviewed-by: Robin Murphy > Avoid the backtrace by only calling dma_set_max_seg_size() if DMA is > supported. > > Cc: Christoph Hellwig > Cc: Robin Murphy > Cc: Ulf Hansson > Signed-off-by: Guenter Roeck > --- > drivers/mmc/core/queue.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c > index d0b3ca8a11f0..4d6844261912 100644 > --- a/drivers/mmc/core/queue.c > +++ b/drivers/mmc/core/queue.c > @@ -388,7 +388,8 @@ static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq, > > blk_queue_rq_timeout(mq->queue, 60 * HZ); > > - dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue)); > + if (mmc_dev(host)->dma_parms) > + dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue)); > > INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler); > INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);