2018-07-27 02:19:56

by Jia-Ju Bai

Subject: [PATCH] input: misc: powermate: Replace GFP_ATOMIC with GFP_KERNEL in powermate_alloc_buffers()

powermate_alloc_buffers() is never called in atomic context.
It calls usb_alloc_coherent() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/input/misc/powermate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/misc/powermate.c b/drivers/input/misc/powermate.c
index 5c8c79623c87..e8de3aaf9f63 100644
--- a/drivers/input/misc/powermate.c
+++ b/drivers/input/misc/powermate.c
@@ -277,7 +277,7 @@ static int powermate_input_event(struct input_dev *dev, unsigned int type, unsig
static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
{
pm->data = usb_alloc_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
- GFP_ATOMIC, &pm->data_dma);
+ GFP_KERNEL, &pm->data_dma);
if (!pm->data)
return -1;

--
2.17.0

2018-07-27 18:35:02

by Dmitry Torokhov

Subject: Re: [PATCH] input: misc: powermate: Replace GFP_ATOMIC with GFP_KERNEL in powermate_alloc_buffers()

On Fri, Jul 27, 2018 at 10:17:23AM +0800, Jia-Ju Bai wrote:
> powermate_alloc_buffers() is never called in atomic context.
> It calls usb_alloc_coherent() with GFP_ATOMIC, which is not necessary.
> GFP_ATOMIC can be replaced with GFP_KERNEL.
>
> This is found by a static analysis tool named DCNS written by myself.
>
> Signed-off-by: Jia-Ju Bai <[email protected]>

Applied, thank you.

> ---
> drivers/input/misc/powermate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/input/misc/powermate.c b/drivers/input/misc/powermate.c
> index 5c8c79623c87..e8de3aaf9f63 100644
> --- a/drivers/input/misc/powermate.c
> +++ b/drivers/input/misc/powermate.c
> @@ -277,7 +277,7 @@ static int powermate_input_event(struct input_dev *dev, unsigned int type, unsig
> static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
> {
> pm->data = usb_alloc_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
> - GFP_ATOMIC, &pm->data_dma);
> + GFP_KERNEL, &pm->data_dma);
> if (!pm->data)
> return -1;
>
> --
> 2.17.0
>

--
Dmitry