Re: [PATCH v4 05/14] serial: 8250_mxpcie: offload XON/XOFF flow control to MUEx50 hardware

[Crescent Hsieh <crescentcy.hsieh@moxa.com>]

On Thu, Jul 30, 2026 at 07:49:43AM +0200, Jiri Slaby wrote:
> On 29. 07. 26, 8:05, Crescent Hsieh wrote:
> > +	serial_out(up, MOXA_PUART_XOFF1, STOP_CHAR(tty));
> > +	serial_out(up, MOXA_PUART_XOFF2, STOP_CHAR(tty));
> > +
> > +	efr &= ~(MOXA_PUART_EFR_RX_FLOW_MASK | MOXA_PUART_EFR_TX_FLOW_MASK);
> 
> This is not needed, as you use FIELD_MODIFY(), right?
> 
> > +	val = I_IXON(tty) ? MOXA_PUART_EFR_RX_FLOW_XON1_XOFF1 : MOXA_PUART_EFR_RX_FLOW_DISABLED;
> > +	efr = FIELD_MODIFY(MOXA_PUART_EFR_RX_FLOW_MASK, &efr, val);
> > +
> > +	val = I_IXOFF(tty) ? MOXA_PUART_EFR_TX_FLOW_XON1_XOFF1 : MOXA_PUART_EFR_TX_FLOW_DISABLED;
> > +	efr = FIELD_MODIFY(MOXA_PUART_EFR_TX_FLOW_MASK, &efr, val);
> 
> Assigning back to efr is unnecessary. The reg is updated in-place.

Hi Jiri,

Thanks for your review.

I also noticed the same unnecessary assignment pattern in
[PATCH v4 01/14], in mxpcie8250_set_interface(), and will fix that as
well.

---
Sincerely,
Crescent Hsieh