2017-07-31 08:58:27

by Arnd Bergmann

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

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 <[email protected]>
---
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

2017-08-02 08:20:42

by Marcus Wolf

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

Reviewed-by: Marcus Wolf <[email protected]>

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 <[email protected]>
> ---
> 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
>
>
>