Re: [PATCH 2/4] serial: 8250: of: Load TX FIFO Load Size from DT

[Thor Thayer]

Hi Rob,

On 09/16/2016 02:20 PM, Rob Herring wrote:
> On Thu, Sep 08, 2016 at 11:12:19AM -0500, tthayer@xxxxxxxxxxxxxxxxxxxxx wrote:
> > From: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
> >
> > Initialize the tx_loadsz parameter if it is defined in the
> > device tree.
> >
> > Signed-off-by: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/tty/serial/8250/8250_of.c |    6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
> > index 38963d7..3e4be2f 100644
> > --- a/drivers/tty/serial/8250/8250_of.c
> > +++ b/drivers/tty/serial/8250/8250_of.c
> > @@ -195,6 +195,7 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
> >  	switch (port_type) {
> >  	case PORT_8250 ... PORT_MAX_8250:
> >  	{
> > +		u32 prop;
> >  		struct uart_8250_port port8250;
> >  		memset(&port8250, 0, sizeof(port8250));
> >  		port8250.port = port;
> > @@ -202,6 +203,11 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
> >  		if (port.fifosize)
> >  			port8250.capabilities = UART_CAP_FIFO;
> >
> > +		/* Check for TX fifo load size */
> > +		if (of_property_read_u32(ofdev->dev.of_node,
> > +					 "tx-loadsz", &prop) == 0)
> > +			port8250.tx_loadsz = prop;
>
> This can be simplified to:
>
> of_property_read_u32(ofdev->dev.of_node, "tx-loadsz", &port8250.tx_loadsz);
Yes, I originally had it implemented using that function but then I 
realized the port8250.tx_loadsz is an unsigned int and therefore can 
change size on different platforms.

The assignment handles that. In retrospect, I should probably change 
this to a of_property_read_u8() anyway so that it won't cause compile 
warnings in the smaller architectures.

Thank you for reviewing and the comments.

Thor

> > +
> >  		if (of_property_read_bool(ofdev->dev.of_node,
> >  					  "auto-flow-control"))
> >  			port8250.capabilities |= UART_CAP_AFE;
> > --
> > 1.7.9.5