Re: [PATCH V2 3/3] Adding device_dma_parameters->offset_preserve_mask to NVMe driver.

From: Andy Shevchenko
Date: Mon Feb 01 2021 - 13:57:43 EST


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