Re: [PATCH v4 09/10] tty: serial: use uart_port_tx() helper

From: Jiri Slaby <jirislaby@kernel.org>
To: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	linux-serial <linux-serial@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"Tobias Klauser" <tklauser@distanz.ch>,
	"Richard Genoud" <richard.genoud@gmail.com>,
	"Nicolas Ferre" <nicolas.ferre@microchip.com>,
	"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	"Claudiu Beznea" <claudiu.beznea@microchip.com>,
	"Vladimir Zapolskiy" <vz@mleia.com>,
	"Liviu Dudau" <liviu.dudau@arm.com>,
	"Sudeep Holla" <sudeep.holla@arm.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Fabio Estevam" <festevam@gmail.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Andreas Färber" <afaerber@suse.de>,
	"Manivannan Sadhasivam" <mani@kernel.org>
Subject: Re: [PATCH v4 09/10] tty: serial: use uart_port_tx() helper
Date: Tue, 20 Sep 2022 10:56:10 +0200	[thread overview]
Message-ID: <9cd3b4bc-64e8-7603-f2e7-8260bdb8b019@kernel.org> (raw)
In-Reply-To: <87251b8a-d955-e6dd-94df-c7621e72bac@linux.intel.com>

On 20. 09. 22, 10:54, Ilpo Järvinen wrote:
> On Tue, 20 Sep 2022, Jiri Slaby wrote:
> 
>> uart_port_tx() is a new helper to send characters to the device. Use it
>> in these drivers.
>>
>> Cc: Tobias Klauser <tklauser@distanz.ch>
>> Cc: Richard Genoud <richard.genoud@gmail.com>
>> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
>> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
>> Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
>> Cc: Vladimir Zapolskiy <vz@mleia.com>
>> Cc: Liviu Dudau <liviu.dudau@arm.com>
>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Shawn Guo <shawnguo@kernel.org>
>> Cc: Sascha Hauer <s.hauer@pengutronix.de>
>> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
>> Cc: Fabio Estevam <festevam@gmail.com>
>> Cc: NXP Linux Team <linux-imx@nxp.com>
>> Cc: "Andreas Färber" <afaerber@suse.de>
>> Cc: Manivannan Sadhasivam <mani@kernel.org>
>> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
>> ---
> 
>> diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
>> index b1cd9a76dd93..53b642ea46ba 100644
>> --- a/drivers/tty/serial/mcf.c
>> +++ b/drivers/tty/serial/mcf.c
>> @@ -327,29 +327,13 @@ static void mcf_rx_chars(struct mcf_uart *pp)
>>   static void mcf_tx_chars(struct mcf_uart *pp)
>>   {
>>   	struct uart_port *port = &pp->port;
>> -	struct circ_buf *xmit = &port->state->xmit;
>> -
>> -	if (port->x_char) {
>> -		/* Send special char - probably flow control */
>> -		writeb(port->x_char, port->membase + MCFUART_UTB);
>> -		port->x_char = 0;
>> -		port->icount.tx++;
>> -		return;
>> -	}
>> -
>> -	while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
>> -		if (uart_circ_empty(xmit))
>> -			break;
>> -		writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
>> -		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
>> -		port->icount.tx++;
>> -	}
>> -
>> -	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
>> -		uart_write_wakeup(port);
>> +	unsigned int pending;
>> +	u8 ch;
>>   
>> -	if (uart_circ_empty(xmit)) {
>> -		mcf_stop_tx(port);
>> +	pending = uart_port_tx(port, ch,
>> +		readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY,
>> +		writeb(ch, port->membase + MCFUART_UTB));
>> +	if (!pending) {
> 
> Why unsigned int pending here and bool pending in the other cases?

Right, I somehow omitted that pending is not used anywhere else. This 
should be bool too, of course.

> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

thanks,
-- 
js
suse labs