Re: Re: [PATCH v6 11/13] serial: 8250_dw: add Ambarella CV75 quirks

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Thu, 10 Sep 2026, Andy Shevchenko wrote:

> On Thu, Sep 10, 2026 at 05:12:52PM +0800, zl020895 wrote:
> 
> > > Wondering if we should undo this in the port's .shutdown() callback.
> > I saw the shutdown path already covers it: dw8250_shutdown() calls
> > serial8250_do_shutdown(), which does
> > 	up->ier = 0;
> > 	serial_port_out(port, UART_IER, 0);
> > so both the IER shadow and hardware IER are cleared, including ETOI.
> 
> Depending on the answer to Ilpo the enabling may need an updated comment
> summarising the above.

I'd prefer removing the entire "Force them ..." sentence, it feels really 
basic detail about how ->ier works. I believe that would resolve your 
concern if relates to what shutdown does for the flag (clears it while 
the comment as is says nothing is supposed to clear it).

> > At 2026-09-10 16:33:14, "Andy Shevchenko" <andriy.shevchenko@linux.intel.com> wrote:
> > >On Fri, Sep 04, 2026 at 02:38:18PM +0800, Long Zhao via B4 Relay wrote:
> 
> ...
> 
> > >> +	/*
> > >> +	 * Ambarella keeps variant IER bits (e.g. ETOI) set for correct RX
> > >> +	 * timeout behaviour. Force them into the 8250 IER shadow so later
> > >> +	 * generic IER updates do not clear them.
> > >> +	 */
> > >
> > >Wondering if we should undo this in the port's .shutdown() callback.
> 
> 

-- 
 i.