# Re: \[PATCH\] net: ethernet: sun4i-emac: free dma descriptor

- From: 李克斯 \<hidden\>
- Date: 2025-09-09 06:43:11 
- List: netdev
- Page: https://ratatoskr.run/netdev/2025/09/3207440
- Thread: https://ratatoskr.run/netdev/2025/08/3193410/t.md

```text
Thank you for the suggestion. I've reviewed the documentation, and setting the reuse flag while reusing descriptors might be a good optimization. I'll make the changes and run some tests. If everything works well, I'll submit a new patch.

> 2025年9月9日 04:26，Jakub Kicinski [ref] 写道：
> 
> On Sun,  7 Sep 2025 19:29:30 +0800 Conley Lee wrote:
>> In the current implementation of the sun4i-emac driver, when using DMA to
>> receive data packets, the descriptor for the current DMA request is not
>> released in the rx_done_callback.
> 
> I wish you elaborated more on the reuse flag not being set :\
> 
>> Fix this by properly releasing the descriptor.
>> 
>> Fixes: 47869e82c8b8 ("sun4i-emac.c: add dma support")
>> Signed-off-by: Conley Lee <redacted>
> 
> Hi Vinod, could you TAL? Is this fix legit or there's something wrong
> with how the DMA engine API is used on this platform?
> https://lore.kernel.org/all/tencent_D434891410B0717BB0BDCB1434969E6EB50A@qq.com/

```