Re: mlx5e:zero-prefix corruption during TCP DMA-BUF RX - help requested

[Dragos Tatulea <dtatulea@nvidia.com>]

On 21.10.26 07:19, jiabin deng wrote:
> Hi Dragos,
> 
> I applied your suggested change to `rq_end_pad_mode()` on the receiver
> and reran the standalone GPU-memory reproducer I sent previously. With
> MTU set to 1500, the single-direction test covered eight message
> sizes, with 50 transfers per size, for a total of 400 transfers.
> 
> All 400 transfers completed successfully. Full payload comparisons
> found zero failing cases, zero incorrect bytes, and zero corrupted
> intervals. The zero-prefix corruption observed in the earlier tests
> did not recur in this patched run.
> 
> Thank you for continuing to investigate this issue and for suggesting
> the fix. I also greatly appreciate the time and effort you and the
> other maintainers dedicate to the open-source community. As a student,
> I am excited to have the opportunity to contribute to the community
> and to learn from this process.
> 
Thank you for your good analysis and fast response!

> I would be happy to help prepare a formal patch with the test results.
> Would you prefer to submit the fix yourself, or would it be helpful
> for me to prepare and submit it based on your suggested change?
> 
I am still waiting for input from the HW folks to understand if this
change is needed for all SHAMPO cases or only specific P2P DMA
cases.

I think you should submit the fix as you did most of the work. Just
give me some time to check the above. I'll ping you hopefully next
week.

Thanks,
Dragos