Re: [PATCH 0/3] serial: Fix support for UPF_SPD_* flags

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Mar 22, 2022 at 04:29:08PM +0200, Andy Shevchenko wrote:
> On Mon, Mar 21, 2022 at 11:07 PM Pali Rohár <pali@kernel.org> wrote:
> >
> > Support for UPF_SPD_* flags is currently broken in more drivers for two
> > reasons. First one is that uart_update_timeout() function does not
> 
> the uart_update_timeout()
> 
> > calculate timeout for UPF_SPD_CUST flag correctly. Second reason is that
> > userspace termios structre is modified by most drivers after each
> 
> structure
> 
> ...
> 
> > (error handling was ommited for simplification)
> 
> omitted
> 
> > After calling set_active_spd_cust_baud() function SPD custom divisor
> > should be active and therefore is_spd_cust_active() should return true.
> >
> > But it is not active (cfgetospeed does not return B38400) and this patch
> > series should fix it. I have tested it with 8250 driver.
> 
> drivers
> 
> > Originally Johan Hovold reported that there may be issue with these
> > ASYNC_SPD_FLAGS in email:
> > https://lore.kernel.org/linux-serial/20211007133146.28949-1-johan@kernel.org/
> >
> >
> > Johan, Greg, could you please test these patches if there is not any
> > regression?
> 
> I'm wondering why we are still supporting this ugly hack?
> Doesn't BOTHER work for you?

Yes, I too do not want to add more support for these old flags.  If they
have not been working, let's not add support for them as obviously no
one is using them.  Let's try to remove them if at all possible.

thanks,

greg k-h