linux-kernel - Re: [PATCH v1 07/31] serial: 8250_mxupci: add GDL-based Rx routine for 8250

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Message-ID: <aTJVz-BZKUjahVSK@moxa-ThinkCentre-M90t>
Date: Fri, 5 Dec 2025 11:47:27 +0800
From: Crescent Hsieh <crescentcy.hsieh@...a.com>
To: Andy Shevchenko <andy.shevchenko@...il.com>
Cc: gregkh@...uxfoundation.org, jirislaby@...nel.org,
	ilpo.jarvinen@...ux.intel.com, linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org
Subject: Re: [PATCH v1 07/31] serial: 8250_mxupci: add GDL-based Rx routine
 for 8250_mxupci

On Sun, Nov 30, 2025 at 07:29:47PM +0200, Andy Shevchenko wrote:
> On Sun, Nov 30, 2025 at 12:43 PM Crescent Hsieh
> <crescentcy.hsieh@...a.com> wrote:
> > -       if (lsr & (UART_LSR_DR | UART_LSR_BI) && !skip_rx)
> > -               lsr = serial8250_rx_chars(up, lsr);
> > -
> > +       if (lsr & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) {
> > +               if (lsr & UART_LSR_BRK_ERROR_BITS)
> > +                       lsr = serial8250_rx_chars(up, lsr);
> > +               else
> > +                       mxupci8250_rx_chars(up);
> > +       }
> 
> Oh, can we reduce ping-pong a bit (the modification of the lines just
> being added earlier in the same patch series)?
> 
> I think you can create a helper to wrap 8250_rx_chars() with split
> version of the almost unreadable conditionals, this will also remove
> the skip_rx variable

I want to confirm whether I understood your suggestion correctly:

Should I first introduce a small wrapper function for Rx processing,
move all the complicated Rx conditions into that wrapper so that
handle_irq() remains short and readable, and then, in a later patch,
introduce the actual custom Rx routine and update the wrapper to call
it?

---
Sincerely,
Crescent Hsieh