Re: [Qemu-devel] [PATCH v5 1/4] net/rocker: Remove the dead error handling

[Philippe Mathieu-Daudé]

Hi Markus,

On 05/23/2017 06:27 AM, Markus Armbruster wrote:
[...]
> There's one more cleanup opportunity:
[...]
> >      if (pci_dma_read(dev, le64_to_cpu(info->desc.buf_addr), info->buf, size)) {
> >          return NULL;
> >      }
>
> None of the pci_dma_read() calls outside rocker check the return value.
> Just as well, because it always returns 0.  Please clean this up in a
> separate followup patch.

It may be the correct way to do it but this sounds like we are missing 
something somewhere... pci_dma_read() calls pci_dma_rw() which always 
returns 0. Why not let it returns void? It is inlined and never used by 
address. Else we should document why returning 0 is correct, and what is 
the reason to not use a void prototype.

pci_dma_rw() calls dma_memory_rw() which does return a boolean value, 
false on success (MEMTX_OK) and true on error (MEMTX_ERROR/DECODE_ERROR)

Regards,

Phil.