Re: [PATCH v3 1/2] tty: serial: qcom_geni_serial: IRQ cleanup

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Oct 15, 2019 at 11:41:03AM +0530, Akash Asthana wrote:
> Move ISR registration from startup to probe function to avoid registering
> it everytime when the port open is called for driver.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
> Changes in v3:
>  - Address review comments on v2 patch.
>  - Using devm_kasprintf instead of scnprintf API.
> 
>  drivers/tty/serial/qcom_geni_serial.c | 30 +++++++++++++++++++-----------
>  1 file changed, 19 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index 14c6306..12dc007 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -9,6 +9,7 @@
>  #include <linux/console.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
> +#include <linux/irq.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> @@ -101,7 +102,7 @@
>  struct qcom_geni_serial_port {
>  	struct uart_port uport;
>  	struct geni_se se;
> -	char name[20];
> +	const char *name;
>  	u32 tx_fifo_depth;
>  	u32 tx_fifo_width;
>  	u32 rx_fifo_depth;
> @@ -830,7 +831,7 @@ static void qcom_geni_serial_shutdown(struct uart_port *uport)
>  	if (uart_console(uport))
>  		console_stop(uport->cons);
>  
> -	free_irq(uport->irq, uport);
> +	disable_irq(uport->irq);
>  	spin_lock_irqsave(&uport->lock, flags);
>  	qcom_geni_serial_stop_tx(uport);
>  	qcom_geni_serial_stop_rx(uport);
> @@ -890,21 +891,14 @@ static int qcom_geni_serial_startup(struct uart_port *uport)
>  	int ret;
>  	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
>  
> -	scnprintf(port->name, sizeof(port->name),
> -		  "qcom_serial_%s%d",
> -		(uart_console(uport) ? "console" : "uart"), uport->line);
> -
>  	if (!port->setup) {
>  		ret = qcom_geni_serial_port_setup(uport);
>  		if (ret)
>  			return ret;
>  	}
> +	enable_irq(uport->irq);
>  
> -	ret = request_irq(uport->irq, qcom_geni_serial_isr, IRQF_TRIGGER_HIGH,
> -							port->name, uport);
> -	if (ret)
> -		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
> -	return ret;
> +	return 0;
>  }
>  
>  static unsigned long get_clk_cfg(unsigned long clk_freq)
> @@ -1297,11 +1291,25 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
>  	port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
>  	port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
>  
> +	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
> +			"qcom_geni_serial_%s%d",
> +			uart_console(uport) ? "console" : "uart", uport->line);
> +	if (!port->name)
> +		return ERR_PTR(-ENOMEM);

Why are you returning a pointer when the return type of this function is
int?  Did the compiler not complain?  Shouldn't this just be -ENOMEM?


> +
>  	irq = platform_get_irq(pdev, 0);
>  	if (irq < 0)
>  		return irq;
>  	uport->irq = irq;
>  
> +	irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
> +	ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
> +			IRQF_TRIGGER_HIGH, port->name, uport);
> +	if (ret) {
> +		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);

Why print this out?  Doesn't the function print an error if it fails?

> +		return ret;

See, an int return value :)

thanks,

greg k-h