write stuck in while(1)

[Memarnejad]

Hi, In function process_write_data, repeat condition may lead to while(1). Suppose that user does not specify --tx-bytes: int repeat = (_cl_tx_bytes == 0); so the repeat condition will be 1 and if the following condition is not satisfied, we will stuck in while(1) if (c < actual_write_size) { _write_count_value = _write_data[c]; repeat = 0; } If driver can send all data, then c = actual_write_size which leads the condition not being satisfied and we stuck in while(1)

But the question is that why does it work with some devices? I guess that's because drivers can't send 1024bytes in ONE round (the remaining will be send in the next round ... handled in userspace) and the c < actual_write_size is satisfied and we don't stuck in while(1). But what if the driver can send 1024bytes? Unfortunately, it will get stuck in while(1)

I fixed this issue by simply replacing < with <=. Here is the modification: if (c <= actual_write_size) { _write_count_value = _write_data[c]; repeat = 0; }

[Goshik92]

Hi @Memarnejad, I have the same issue, and it looks like the solution you proposed fixes it. Please consider opening a PR for merging your fix into the main branch.

[andy-shev]

FWIW, It's not uncommon that driver can send even more than 1kB at once with a help of DMA.