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

[Akash Asthana <akashast@codeaurora.org>]

On 10/16/2019 12:28 AM, Greg KH wrote:
> 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?
Sorry about it! I will take care of this in future. I missed it due to 
compiler setting, every warning was not treated as error.
>> +
>>   	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?
The function doesn't print error for every failure paths.
>> +		return ret;
> See, an int return value :)
>
> thanks,
>
> greg k-h

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