[PATCH v3] serial: samsung: Re-factors UART IRQ resource for various Samsung SoC

[PATCH v3] serial: samsung: Re-factors UART IRQ resource for various Samsung SoC

[Tamseel Shams]

In few older Samsung SoCs like s3c2410, s3c2412
and s3c2440, UART IP is having 2 interrupt lines.
However, in other SoCs like s3c6400, s5pv210,
exynos5433, and exynos4210 UART is having only 1
interrupt line. Due to this, "platform_get_irq(platdev, 1)"
call in the driver gives the following warning:
"IRQ index 1 not found" on recent platforms.

This patch re-factors the IRQ resources handling for
each platform and hence fixing the above warnings seen
on some platforms.

Signed-off-by: Tamseel Shams <m.shams@samsung.com>
---
Removed the logic of irq_cnt and directly using
s3c24xx_serial_has_interrupt_mask() to check for
number of interrupt lines.

 drivers/tty/serial/samsung_tty.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 6ef614d8648c..8a955f3d8975 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1908,10 +1908,13 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 	else {
 		port->irq = ret;
 		ourport->rx_irq = ret;
-		ourport->tx_irq = ret + 1;
+		if (s3c24xx_serial_has_interrupt_mask(port))
+			ourport->tx_irq = ret;
+		else
+			ourport->tx_irq = ret + 1;
 	}
 
-	ret = platform_get_irq(platdev, 1);
+	ret = platform_get_irq_optional(platdev, 1);
 	if (ret > 0)
 		ourport->tx_irq = ret;
 	/*
-- 
2.17.1

Re: [PATCH v3] serial: samsung: Re-factors UART IRQ resource for various Samsung SoC

[Krzysztof Kozlowski]

On Sat, Jul 04, 2020 at 07:36:46PM +0530, Tamseel Shams wrote:
> In few older Samsung SoCs like s3c2410, s3c2412
> and s3c2440, UART IP is having 2 interrupt lines.
> However, in other SoCs like s3c6400, s5pv210,
> exynos5433, and exynos4210 UART is having only 1
> interrupt line. Due to this, "platform_get_irq(platdev, 1)"
> call in the driver gives the following warning:
> "IRQ index 1 not found" on recent platforms.
> 
> This patch re-factors the IRQ resources handling for
> each platform and hence fixing the above warnings seen
> on some platforms.
> 
> Signed-off-by: Tamseel Shams <m.shams@samsung.com>
> ---
> Removed the logic of irq_cnt and directly using
> s3c24xx_serial_has_interrupt_mask() to check for
> number of interrupt lines.
> 
>  drivers/tty/serial/samsung_tty.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index 6ef614d8648c..8a955f3d8975 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -1908,10 +1908,13 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
>  	else {
>  		port->irq = ret;
>  		ourport->rx_irq = ret;
> -		ourport->tx_irq = ret + 1;
> +		if (s3c24xx_serial_has_interrupt_mask(port))
> +			ourport->tx_irq = ret;

Hi,

I don't understand: Why do you assign here the same interrupt as RX?

Best regards,
Krzysztof

> +		else
> +			ourport->tx_irq = ret + 1;
>  	}
>  
> -	ret = platform_get_irq(platdev, 1);
> +	ret = platform_get_irq_optional(platdev, 1);
>  	if (ret > 0)
>  		ourport->tx_irq = ret;
>  	/*
> -- 
> 2.17.1
> 

RE: [PATCH v3] serial: samsung: Re-factors UART IRQ resource for various Samsung SoC

[M Tamseel Shams]

> > In few older Samsung SoCs like s3c2410, s3c2412 and s3c2440, UART IP
> > is having 2 interrupt lines.
> > However, in other SoCs like s3c6400, s5pv210, exynos5433, and
> > exynos4210 UART is having only 1 interrupt line. Due to this,
> > "platform_get_irq(platdev, 1)"
> > call in the driver gives the following warning:
> > "IRQ index 1 not found" on recent platforms.
> >
> > This patch re-factors the IRQ resources handling for each platform and
> > hence fixing the above warnings seen on some platforms.
> >
> > Signed-off-by: Tamseel Shams <m.shams@samsung.com>
> > ---
> > Removed the logic of irq_cnt and directly using
> > s3c24xx_serial_has_interrupt_mask() to check for number of interrupt
> > lines.
> >
> >  drivers/tty/serial/samsung_tty.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/tty/serial/samsung_tty.c
> > b/drivers/tty/serial/samsung_tty.c
> > index 6ef614d8648c..8a955f3d8975 100644
> > --- a/drivers/tty/serial/samsung_tty.c
> > +++ b/drivers/tty/serial/samsung_tty.c
> > @@ -1908,10 +1908,13 @@ static int s3c24xx_serial_init_port(struct
> s3c24xx_uart_port *ourport,
> >  	else {
> >  		port->irq = ret;
> >  		ourport->rx_irq = ret;
> > -		ourport->tx_irq = ret + 1;
> > +		if (s3c24xx_serial_has_interrupt_mask(port))
> > +			ourport->tx_irq = ret;
> 
> Hi,
> 
> I don't understand: Why do you assign here the same interrupt as RX?
> 
> Best regards,
> Krzysztof
> 
Hi Krzysztof,
I was assigning the same interrupt to Tx and Rx for UART, which have one interrupt line, 
but ourport->tx_irq is never used for those UART's. So, leaving it as it was.
The change now is using platform_get_irq_optional () instead of platform_get_irq ()
to avoid false-positive error.

Thanks & Regards,
Tamseel