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

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Date:   Wed, 16 Dec 2020 09:25:47 +0100
From:   Jiri Slaby <jirislaby@...nel.org>
To:     József Horváth <info@...istro.hu>,
        '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 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