Subject: Re: linux-next: manual merge of the tty tree with the tty.current tree

From: Greg KH <[email-masked]>
Date: Mon, 16 Oct 2023 10:20:10 +0200

On Wed, Oct 04, 2023 at 08:38:51AM +0200, Greg KH wrote:
> On Wed, Oct 04, 2023 at 01:14:32PM +1100, Stephen Rothwell wrote:
> > Hi all,
> > 
> > On Wed, 4 Oct 2023 12:55:31 +1100 Stephen Rothwell <[email-masked]> wrote:
> > >
> > > Today's linux-next merge of the tty tree got a conflict in:
> > > 
> > >   drivers/tty/serial/serial_core.c
> > > 
> > > between commit:
> > > 
> > >   8679328eb859 ("serial: Reduce spinlocked portion of uart_rs485_config()")
> > > 
> > > from the tty.current tree and commit:
> > > 
> > >   559c7ff4e324 ("serial: core: Use port lock wrappers")
> > > 
> > > from the tty tree.
> > > 
> > > I fixed it up (see below) and can carry the fix as necessary. This
> > > is now fixed as far as linux-next is concerned, but any non trivial
> > > conflicts should be mentioned to your upstream maintainer when your tree
> > > is submitted for merging.  You may also want to consider cooperating
> > > with the maintainer of the conflicting tree to minimise any particularly
> > > complex conflicts.
> > 
> > Not quite right :-(  This is what I used:
> > 
> > diff --cc drivers/tty/serial/serial_core.c
> > index ca26a8aef2cb,b32bbd7aa3d3..ae1d6782ea0e
> > --- a/drivers/tty/serial/serial_core.c
> > +++ b/drivers/tty/serial/serial_core.c
> > @@@ -1413,9 -1409,7 +1413,9 @@@ static int uart_rs485_config(struct uar
> >   	uart_sanitize_serial_rs485(port, rs485);
> >   	uart_set_rs485_termination(port, rs485);
> >   
> > - 	spin_lock_irqsave(&port->lock, flags);
> > ++	uart_port_lock_irqsave(port, &flags);
> >   	ret = port->rs485_config(port, NULL, rs485);
> > - 	spin_unlock_irqrestore(&port->lock, flags);
> > ++	uart_port_unlock_irqrestore(port, flags);
> >   	if (ret)
> >   		memset(rs485, 0, sizeof(*rs485));
> >   
> > @@@ -2480,12 -2474,13 +2480,12 @@@ int uart_resume_port(struct uart_drive
> >   			if (ret == 0) {
> >   				if (tty)
> >   					uart_change_line_settings(tty, state, NULL);
> >  +				uart_rs485_config(uport);
> > - 				spin_lock_irq(&uport->lock);
> > + 				uart_port_lock_irq(uport);
> >   				if (!(uport->rs485.flags & SER_RS485_ENABLED))
> >   					ops->set_mctrl(uport, uport->mctrl);
> >  -				else
> >  -					uart_rs485_config(uport);
> >   				ops->start_tx(uport);
> > - 				spin_unlock_irq(&uport->lock);
> > + 				uart_port_unlock_irq(uport);
> >   				tty_port_set_initialized(port, true);
> >   			} else {
> >   				/*
> > @@@ -2592,10 -2587,10 +2592,10 @@@ uart_configure_port(struct uart_driver 
> >   		port->mctrl &= TIOCM_DTR;
> >   		if (!(port->rs485.flags & SER_RS485_ENABLED))
> >   			port->ops->set_mctrl(port, port->mctrl);
> > - 		spin_unlock_irqrestore(&port->lock, flags);
> >  -		else
> >  -			uart_rs485_config(port);
> > + 		uart_port_unlock_irqrestore(port, flags);
> >   
> >  +		uart_rs485_config(port);
> >  +
> >   		/*
> >   		 * If this driver supports console, and it hasn't been
> >   		 * successfully registered yet, try to re-register it.
> > 
> > 
> > -- 
> > Cheers,
> > Stephen Rothwell
> 
> Thanks, looks good, I'll use this when I resolve the merge conflict when
> it hits my branches.

This should now be resolved in my tree, thanks!

greg k-h