linux-kernel - Re: [PATCH v6] Serial: silabs si4455 serial driver

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Message-ID: <20210105101211.GA9717@dev>
Date:   Tue, 5 Jan 2021 10:12:11 +0000
From:   József Horváth <info@...istro.hu>
To:     Jiri Slaby <jirislaby@...nel.org>
Cc:     'Greg Kroah-Hartman' <gregkh@...uxfoundation.org>,
        'Rob Herring' <robh+dt@...nel.org>,
        linux-serial@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v6] Serial: silabs si4455 serial driver

On Wed, Dec 16, 2020 at 09:25:47AM +0100, Jiri Slaby wrote:
> On 15. 12. 20, 19:15, József Horváth wrote:
> > --- /dev/null
> > +++ b/drivers/tty/serial/si4455.c
> > @@ -0,0 +1,1372 @@
> ...
> > +static int si4455_write_data(struct uart_port *port, u8 command, int poll,
> > +			     int length, const u8 *data)
> > +{
> > +	int ret = 0;
> > +	u8 *data_out;
> > +
> > +	if (poll) {
> > +		ret = si4455_poll_cts(port);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +
> > +	data_out = kzalloc(1 + length, GFP_KERNEL);
> > +	if (!data_out)
> > +		return -ENOMEM;
> > +
> > +	data_out[0] = command;
> > +	memcpy(&data_out[1], data, length);
> > +	ret = spi_write(to_spi_device(port->dev), data_out, 1 + length);
> > +	if (ret) {
> > +		dev_err(port->dev,
> > +			"%s: spi_write error (%i)\n", __func__, ret);
> > +	}
> > +
> > +	kfree(data_out);
> > +
> > +	return ret;
> > +}
> > +
> > +static void si4455_set_power(struct si4455_port *priv, int on)
> 
> "on" can be bool here. And "poll" in earlier functions. And "on" in later
> ones.
> 
> > +{
> > +	if (!priv->shdn_gpio)
> > +		return;
> > +	if (on) {
> > +		gpiod_direction_output(priv->shdn_gpio, 0);
> > +		usleep_range(4000, 5000);
> > +		gpiod_set_value(priv->shdn_gpio, 1);
> > +		usleep_range(4000, 5000);
> > +	} else {
> > +		gpiod_direction_output(priv->shdn_gpio, 0);
> > +	}
> 
> The above can be simpler:
> 
> gpiod_direction_output(priv->shdn_gpio, 0);
> 
> if (on) {
> 	usleep_range(4000, 5000);
> 	gpiod_set_value(priv->shdn_gpio, 1);
> 	usleep_range(4000, 5000);
> }
> 
> > +static void si4455_handle_rx_pend(struct si4455_port *s)
> > +{
> > +	struct uart_port *port = &s->port;
> > +	u8 *data = NULL;
> 
> Unused initialization.
> 
> > +	int sret = 0;
> > +	int i = 0;
> > +
> > +	if (s->package_size == 0) {
> > +		//TODO: variable packet length
> > +		dev_err(port->dev, "%s: variable packet length is not supported by the driver\n",
> > +			__func__);
> > +		return;
> > +	}
> > +
> > +	data = kzalloc(s->package_size, GFP_KERNEL);
> 
> Missing check of data.
> 
> > +	sret = si4455_end_rx(port, s->package_size, data);
> > +	if (sret) {
> > +		dev_err(port->dev, "%s: si4455_end_rx error (%i)\n",
> > +			__func__, sret);
> > +	} else {
> > +		for (i = 0; i < s->package_size; i++) {
> > +			uart_insert_char(port, 0, 0, data[i], TTY_NORMAL);
> > +			port->icount.rx++;
> > +		}
> > +		tty_flip_buffer_push(&port->state->port);
> > +	}
> > +	kfree(data);
> > +}
> ...
> thanks,
> -- 
> js
> suse labs

Thank you for suggestions.

Üdvözlettel / Best regards:
József Horváth