Re: [PATCH v3 0/4] tty: TX helpers

[Jiri Slaby]

On 07. 09. 22, 16:56, Arnd Bergmann wrote:
> On Wed, Sep 7, 2022, at 3:52 PM, Russell King (Oracle) wrote:
> > On Wed, Sep 07, 2022 at 02:36:37PM +0200, Greg Kroah-Hartman wrote:
> >
> > Of course, it would have been nicer to see the definition of this
> > macro, because then we can understand what the "ch" argument is to
> > this macro, and how that relates to the macro argument that is
> > shown in the example as a writel().
>
> I pulled out the 'ch' variable from the macro to avoid having
> the macro define local variables that are then passed to the
> inner expressions.

Note that I had "port" and "ch" as a part of the macro parameters in 
[v2], but it didn't help the situation much.
> > Maybe a more complete example would help clear up the confusion?
> > Arnd?
>
> Here is a patch on top of the series that would implement the
> uart_port_tx_helper_limited() and uart_port_tx_helper()
> macros that can be used directly from drivers in place of defining
> local functions, with the (alphabetically) first two drivers
> converted to that.

If there are no objections, I will push the patches this directorin. I 
like this more than [v2] or [v3] (the helper macros). Actually, I 
mentioned this wait_event() style in [v1], but I perhaps simplified the 
concept too much to completely eliminate the need of a wrapper function. 
And that made it too complicated/too hard to understand.

Except I'd drop the "_helper" part from the name. Originally (in [v1]), 
I had uart_port_tx() and uart_port_tx_limited() functions. In [v2+v3], I 
added _helper to avoid confusion as we were generating a helpers using 
the macros. Yes, technically, uart_port_tx() is still a helper, but I 
think it's superfluous to have it in the name now.

thanks,
--
js
suse labs