Re: [PATCH v4 2/8] scpi: Add alternative legacy structures, functions and macros

[Sudeep Holla]

On 19/10/16 11:37, Sudeep Holla wrote:
> On 19/10/16 11:28, Neil Armstrong wrote:
> > On 10/17/2016 01:16 PM, Sudeep Holla wrote:
>
> [...]
>
> > > and the above 2 can be moved out of the conditions, no ?
> > >
> > > if (scpi_info->is_legacy) {
> > >     struct legacy_scpi_shared_mem *mem = ch->rx_payload;
> > >     len = match->rx_len;
> > > } else {
> > >     struct scpi_shared_mem *mem = ch->rx_payload;
> > >     len = min(match->rx_len, CMD_SIZE(cmd));
> > > }
> > > match->status = le32_to_cpu(mem->status);
> > > memcpy_fromio(match->rx_buf, mem->payload, len);
> > >
> > > should work.
> >
> > Well, we will have "error: ‘mem’ undeclared (first use in this
> > function)" since mem is not declared outside the if/else.
> >
> > I don't see good solutions even with an union.
>
> Right, I missed to see that. You can leave it as you had before then.
>
>
> [...]
> > > > > >      if (t->rx_buf) {
> > > > > >          if (!(++ch->token))
> > > > > >              ++ch->token;
> > > > > >          ADD_SCPI_TOKEN(t->cmd, ch->token);
> > > > > > +        if (scpi_info->is_legacy)
> > > > > > +            t->slot = t->cmd;
> > > > >
> > > > > I thought passing token was not an issue from your previous response,
> > > > > but you are overriding it here, why ?
> > > >
> > > > Indeed, I can leave it, but it's useless since it won't serve to
> > > > distinguish multiple similar commands.
> > >
> > > OK, I don't see any point in such micro optimization, so please
> > > retain it.
> >
> > I misread my code, I leaved the token passing, but I copy back the
> > cmd  to the slot which is used by the MHU.
> > If I remove the "t->slot = t->cmd;", the token won't be passed to the
> > FW.
>
> Right, sorry I think I misled you :)

On the other hand, if we are unable to use that in the driver as you
just have FIFO in the list for this legacy mode, I think we can drop it
completely. I know I had argued otherwise before, but that was before I
realized that we need to keep FIFO in the list ;). Let me know if you
are OK to drop it.

--
Regards,
Sudeep