[PATCH] staging: pi433: reduce stack size in tx thread

[PATCH] staging: pi433: reduce stack size in tx thread

[Arnd Bergmann]

Putting a 900 byte array on the stack is a clearly too much in the
kernel, and sometimes results in warnings like:

drivers/staging/pi433/pi433_if.c: In function 'pi433_tx_thread':
drivers/staging/pi433/pi433_if.c:645:1: error: the frame size of 1028 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

This moves the buffer into the dynamically allocated per-device
structure.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/staging/pi433/pi433_if.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
index ed737f4b1e77..ec9811ae4735 100644
--- a/drivers/staging/pi433/pi433_if.c
+++ b/drivers/staging/pi433/pi433_if.c
@@ -92,6 +92,7 @@ struct pi433_device {
 	struct task_struct	*tx_task_struct;
 	wait_queue_head_t	tx_wait_queue;
 	u8			free_in_fifo;
+	char			buffer[MAX_MSG_SIZE];
 
 	/* rx related values */
 	struct pi433_rx_cfg	rx_cfg;
@@ -471,7 +472,7 @@ pi433_tx_thread(void *data)
 	struct pi433_device *device = data;
 	struct spi_device *spi = device->spi; /* needed for SET_CHECKED */
 	struct pi433_tx_cfg tx_cfg;
-	u8     buffer[MAX_MSG_SIZE];
+	u8     *buffer = device->buffer;
 	size_t size;
 	bool   rx_interrupted = false;
 	int    position, repetitions;
-- 
2.9.0

Re: [PATCH] staging: pi433: reduce stack size in tx thread

[Wolf Entwicklungen]

Reviewed-by: Marcus Wolf <linux@wolf-entwicklungen.de>

Maybe tx_buffer is a bit more clearly then buffer.

Thanks,

Marcus

Am Mo, 31.07.2017, 10:57 schrieb Arnd Bergmann:
> Putting a 900 byte array on the stack is a clearly too much in the
> kernel, and sometimes results in warnings like:
>
> drivers/staging/pi433/pi433_if.c: In function 'pi433_tx_thread':
> drivers/staging/pi433/pi433_if.c:645:1: error: the frame size of 1028 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
>
> This moves the buffer into the dynamically allocated per-device
> structure.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/staging/pi433/pi433_if.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
> index ed737f4b1e77..ec9811ae4735 100644
> --- a/drivers/staging/pi433/pi433_if.c
> +++ b/drivers/staging/pi433/pi433_if.c
> @@ -92,6 +92,7 @@ struct pi433_device {
>  	struct task_struct	*tx_task_struct;
>  	wait_queue_head_t	tx_wait_queue;
>  	u8			free_in_fifo;
> +	char			buffer[MAX_MSG_SIZE];
>
>  	/* rx related values */
>  	struct pi433_rx_cfg	rx_cfg;
> @@ -471,7 +472,7 @@ pi433_tx_thread(void *data)
>  	struct pi433_device *device = data;
>  	struct spi_device *spi = device->spi; /* needed for SET_CHECKED */
>  	struct pi433_tx_cfg tx_cfg;
> -	u8     buffer[MAX_MSG_SIZE];
> +	u8     *buffer = device->buffer;
>  	size_t size;
>  	bool   rx_interrupted = false;
>  	int    position, repetitions;
> --
> 2.9.0
>
>
>