Re: [PATCH] serial: 8250: Fix THRE flag usage for CAP_MINI

[Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Tue, 2017-06-27 at 22:00 +0100, Phil Elwell wrote:
> On 27/06/2017 18:52, Andy Shevchenko wrote:
> > On Tue, 2017-06-27 at 11:30 +0100, Phil Elwell wrote:
> > > On 27/06/2017 10:15, Andy Shevchenko wrote:
> > > > On Mon, 2017-06-26 at 16:15 +0100, Phil Elwell wrote:

> > > > > Besides, the "HFIFO" capability looks a lot like quirk to me.
> > > > 
> > > > To me either, which raises a question "Should it be fixed
> > > > accordingly?"
> > > 
> > > If I was going to make these quirks, are we simply talking about
> > > renaming the
> > > capability or is there another mechanism? I've found the 8250_pci
> > > quirks, and
> > > they look quite different.
> > 
> > Okay, we have several types of flags in the code
> > 1. Capabilities: UART_CAP: looks like it defines features of
> > hardware
> > solely for 8250 compatible devices.
> > 2. Flags as quirks UPF_<something, not all of them> (I have a patch
> > to
> > convert them to quirks, need by the way to update and resend): they
> > are
> > for any serial devices.
> > 3. Flags as capabilities: UPF_<the rest>, similar function as
> > UART_CAP,
> > but for any serial device.
> > 
> > > 
> > > I'm also happy to make this code conditional on
> > > CONFIG_SERIAL_8250_BCM2835AUX
> > > if that is more acceptable.
> > 
> > No, it is undesired.
> > 
> > Can you describe which one from the above suits the best for your
> > case?
> 
> This bug I am trying to work around is found in the 8250
> implementation of
> one family of CPUs, so I would say capabilities are the best fit
> because
> they are specific to 8250 drivers.

Yeah, looks like UART_CAP suits the best for now.

One more comment that UART_CAP_* gather capabilities and quirks at the
same time.



-- 
Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Intel Finland Oy