[PATCH net] net: airoha: Add retry mechanism to airoha_qdma_set_trtcm_param()

[Leto Liu (刘涛)]

>I think the issue reported by sashiko in [0] is valid and it needs to be addressed in v2, but since I am not the original author of the patch, I will let Brown or Leto comment on it.
>
>Regards,
>Lorenzo
>
Thanks for the careful review — you are absolutely right.
In the current version, the immediate call to airoha_qdma_get_trtcm_param() can indeed clobber the write command we just issued. That helper programs REG_TRTCM_CFG_PARAM() to start a read transaction, so without first waiting for TRTCM_PARAM_RW_DONE_MASK after the write, we may overwrite the command register before the hardware has latched/finished the write. The added wmb() only enforces the ordering between the DATA and CFG writes, but it does not guarantee the write transaction has completed.
I will address this by restoring the DONE polling after the write, and only then performing the read-back verification (i.e. “write → poll DONE → read-back → compare”, with retries as needed). Also, to avoid clobbering the val argument, the poll will use a separate temporary variable.
I have revised the patch into a v2 version based on this approach, and it is currently under testing and validation. Since this is an intermittent issue, I am running long-duration stability tests. I expect to provide the v2 patch by next Monday.

Best Regards, Leto