Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: jq10xaR0xQKBUZoy5qhb2WCnTxEYfRw4LHXFfLqdwd6175v1LbGzrkFsurQaDk04PLcKplWekf
 x9vfjsP4TQXw==
IronPort-SDR: bO/77yFnFXEOvVyCwMRy9yRPe9Z8Uz08vIlmz+yDqMAbErP+xmmIjp8vozdpxGVV29C+RLOqEn
 iFkP5v0/f/hQ==
Date:   Mon, 1 Feb 2021 20:55:40 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Jianxiong Gao <jxgao@google.com>
Cc:     erdemaktas@google.com, marcorr@google.com, hch@lst.de,
        m.szyprowski@samsung.com, robin.murphy@arm.com,
        gregkh@linuxfoundation.org, saravanak@google.com,
        heikki.krogerus@linux.intel.com, rafael.j.wysocki@intel.com,
        dan.j.williams@intel.com, bgolaszewski@baylibre.com,
        jroedel@suse.de, iommu@lists.linux-foundation.org,
        konrad.wilk@oracle.com, kbusch@kernel.org, axboe@fb.com,
        sagi@grimberg.me, linux-nvme@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 3/3] Adding
 device_dma_parameters->offset_preserve_mask to NVMe driver.
Message-ID: <YBhOrK+kea7PNmXn@smile.fi.intel.com>
References: <20210201183017.3339130-1-jxgao@google.com>
 <20210201183017.3339130-4-jxgao@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210201183017.3339130-4-jxgao@google.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Precedence: bulk

On Mon, Feb 01, 2021 at 10:30:17AM -0800, Jianxiong Gao wrote:
> NVMe driver relies on the address offset to function properly.
> This patch adds the offset preserve mask to NVMe driver when mapping
> via dma_map_sg_attrs and unmapping via nvme_unmap_sg. The mask
> depends on the page size defined by CC.MPS register of NVMe
> controller.

...

>  	if (is_pci_p2pdma_page(sg_page(iod->sg)))
>  		nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg,
>  				iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN);
>  	else
>  		nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,
>  					     rq_dma_dir(req), DMA_ATTR_NO_WARN);
> +
> +	offset_ret = dma_set_min_align_mask(dev->dev, 0);
> +	if (offset_ret) {
> +		dev_warn(dev->dev, "dma_set_min_align_mask failed to reset offset\n");
> +		goto out_free_sg;
> +	}

Seems like rebasing effect which makes empty line goes in the middle of some
other group of code lines.

>  	if (!nr_mapped)
>  		goto out_free_sg;

Perhaps it should be here?

-- 
With Best Regards,
Andy Shevchenko