[PATCH v4] serial: samsung: change to platform_get_irq_optional

[PATCH v4] serial: samsung: change to platform_get_irq_optional

[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 false-positive error:
"IRQ index 1 not found" on recent platforms.

This patch replaces the platform_get_irq() call with
platform_get_irq_optional() and hence avoiding the
false-positive error.

Signed-off-by: Tamseel Shams <m.shams@samsung.com>
---
Commit message is changed.
Addressed Krzysztof's previous comment.
 
 drivers/tty/serial/samsung_tty.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 6ef614d8648c..c44582011b9b 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1911,7 +1911,7 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 		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 v4] serial: samsung: change to platform_get_irq_optional

[Krzysztof Kozlowski]

On Mon, Jul 13, 2020 at 07:25:31PM +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 false-positive error:
> "IRQ index 1 not found" on recent platforms.
> 
> This patch replaces the platform_get_irq() call with
> platform_get_irq_optional() and hence avoiding the
> false-positive error.

The error is not a false positive on S3C platforms, but a real error.
The existing code did not handle missing TX IRQ but at least printed a
message.  Your change hides the message.

The real problem here is a missing error handling for TX interrupt.
Solving this one, would solve also false-positive error message on newer
SoCs.

Best regards,
Krzysztof

[PATCH v4] serial: samsung: change to platform_get_irq_optional

[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 false-positive error:
"IRQ index 1 not found" on recent platforms.

This patch replaces the platform_get_irq() call with
platform_get_irq_optional() and hence avoiding the
false-positive error.

Signed-off-by: Tamseel Shams <m.shams@samsung.com>
---
Commit message is changed.
Addressed Krzysztof's previous comment.
 
 drivers/tty/serial/samsung_tty.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 6ef614d8648c..c44582011b9b 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1911,7 +1911,7 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 		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 v4] serial: samsung: change to platform_get_irq_optional

[M Tamseel Shams]

> -----Original Message-----
> From: Tamseel Shams <m.shams@samsung.com>
> Sent: Monday, June 21, 2021 10:18 AM
> To: kgene@kernel.org; krzk@kernel.org; gregkh@linuxfoundation.org;
> jslaby@suse.com
> Cc: linux-arm-kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org;
> linux-serial@vger.kernel.org; linux-kernel@vger.kernel.org;
> alim.akhtar@samsung.com; ajaykumar.rs@samsung.com; Tamseel Shams
> <m.shams@samsung.com>
> Subject: [PATCH v4] serial: samsung: change to platform_get_irq_optional
> 
> 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 false-positive error:
> "IRQ index 1 not found" on recent platforms.
> 
> This patch replaces the platform_get_irq() call with
> platform_get_irq_optional() and hence avoiding the false-positive error.
> 
> Signed-off-by: Tamseel Shams <m.shams@samsung.com>
> ---
> Commit message is changed.
> Addressed Krzysztof's previous comment.
> 
>  drivers/tty/serial/samsung_tty.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index 6ef614d8648c..c44582011b9b 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -1911,7 +1911,7 @@ static int s3c24xx_serial_init_port(struct
> s3c24xx_uart_port *ourport,
>  		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;
>  	/*
> --
> 

Please ignore this patch.
Sorry for the spam.

Thanks & Regards,
Tamseel Shams