Re: [PATCH 2/2] serial: 8250: Add support for 8250/16550 as MFD function

From: Esben Haabendal
Date: Tue May 14 2019 - 08:43:17 EST


Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> writes:

> On Tue, May 14, 2019 at 11:47:41AM +0100, Lee Jones wrote:
>> On Tue, 14 May 2019, Esben Haabendal wrote:
>>
>> > Lee Jones <lee.jones@xxxxxxxxxx> writes:
>> >
>> > > On Tue, 07 May 2019, Esben Haabendal wrote:
>> > >
>> > >> Lee Jones <lee.jones@xxxxxxxxxx> writes:
>> > >>
>> > >> > On Fri, 26 Apr 2019, Esben Haabendal wrote:
>> > >> >
>> > >> >> The serial8250-mfd driver is for adding 8250/16550 UART ports as functions
>> > >> >> to an MFD driver.
>> > >> >>
>> > >> >> When calling mfd_add_device(), platform_data should be a pointer to a
>> > >> >> struct plat_serial8250_port, with proper settings like .flags, .type,
>> > >> >> .iotype, .regshift and .uartclk. Memory (or ioport) and IRQ should be
>> > >> >> passed as cell resources.
>> > >> >
>> > >> > What? No, please!
>> > >> >
>> > >> > If you *must* create a whole driver just to be able to use
>> > >> > platform_*() helpers (which I don't think you should), then please
>> > >> > call it something else. This doesn't have anything to do with MFD.
>> > >>
>> > >> True.
>> > >>
>> > >> I really don't think it is a good idea to create a whole driver just to
>> > >> be able to use platform_get_*() helpers. And if I am forced to do this,
>> > >> because I am unable to convince Andy to improve the standard serial8250
>> > >> driver to support that, it should be called MFD. The driver would be
>> > >
>> > > I assume you mean "shouldn't"?
>> >
>> > Of-course.
>> >
>> > >> generally usable for all usecases where platform_get_*() works.
>> > >>
>> > >> I don't have any idea what to call such a driver. It really would just
>> > >> be a fork of the current serial8250 driver, just allowing use of
>> > >> platform_get_*(), supporting exactly the same hardware.
>> > >>
>> > >> I am still hoping that we can find a way to improve serial8250 to be
>> > >> usable in these cases.
>> > >
>> > > Me too.
>> >
>> > Unfortunately, I don't seem to be able to convince Andy to accept
>> > something like that.
>>
>> Andy is not he Maintainer.
>>
>> What are Greg and Jiri's opinions?
>
> I've been ignoring all of this at the moment because of the 5.2-rc merge
> window. I'll look at it after -rc1 is out.
>
> thanks,
> greg k-h

Great, thanks!

I will try ad hold back with this thread until you get back to it.

/Esben