From: Jason Gunthorpe <jgg@nvidia.com>
To: Junxian Huang <huangjunxian6@hisilicon.com>
Cc: leon@kernel.org, linux-rdma@vger.kernel.org, linuxarm@huawei.com,
tangchengchang@huawei.com
Subject: Re: [PATCH for-next 2/2] RDMA/hns: Fix wrong maximum DMA segment size
Date: Fri, 4 Apr 2025 10:27:57 -0300 [thread overview]
Message-ID: <20250404132757.GA1336818@nvidia.com> (raw)
In-Reply-To: <bd0c0fa5-7579-8767-8c18-73fd5459de10@hisilicon.com>
On Wed, Apr 02, 2025 at 12:05:36PM +0800, Junxian Huang wrote:
>
>
> On 2025/4/2 0:39, Jason Gunthorpe wrote:
> > On Thu, Mar 27, 2025 at 07:47:24PM +0800, Junxian Huang wrote:
> >> @@ -763,7 +763,7 @@ static int hns_roce_register_device(struct hns_roce_dev *hr_dev)
> >> if (ret)
> >> return ret;
> >> }
> >> - dma_set_max_seg_size(dev, UINT_MAX);
> >> + dma_set_max_seg_size(dev, SZ_2G);
> >
> > Are you sure? What do you think this does in the RDMA stack?
> >
>
> This is the maximum DMA segment size when mapping ULP's scatter/gather
> list to DMA address, right?
Yes, but only for ib_sge
But I think there are other possible problems if your HW cannot
implement the full ib_sge :\
Jason
next prev parent reply other threads:[~2025-04-04 13:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-27 11:47 [PATCH for-next 0/2] RDMA/hns: Cleanup and Bugfix Junxian Huang
2025-03-27 11:47 ` [PATCH for-next 1/2] RDMA/hns: Remove unused parameters Junxian Huang
2025-03-27 11:47 ` [PATCH for-next 2/2] RDMA/hns: Fix wrong maximum DMA segment size Junxian Huang
2025-04-01 16:39 ` Jason Gunthorpe
2025-04-02 4:05 ` Junxian Huang
2025-04-04 13:27 ` Jason Gunthorpe [this message]
2025-04-07 13:51 ` Junxian Huang
2025-04-07 13:54 ` Jason Gunthorpe
2025-04-07 18:36 ` [PATCH for-next 0/2] RDMA/hns: Cleanup and Bugfix Jason Gunthorpe
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