2018-09-13 07:53:51

by zhong jiang

Subject: [PATCH v2] HID: logitech: fix a used uninitialized GCC warning

Fix the following compile warning:

drivers/hid/hid-logitech-hidpp.c: In function 'hi_res_scroll_enable':
drivers/hid/hid-logitech-hidpp.c:2714:54: warning: 'multiplier' may be used uninitialized in this function [-Wmaybe-uninitialized]
hidpp->vertical_wheel_counter.resolution_multiplier = multiplier;

Signed-off-by: zhong jiang <[email protected]>
---
v1->v2:
According to Benjamin's suggestion, To initialize the value
and remove the duplicated assignement.

drivers/hid/hid-logitech-hidpp.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 5f0c080..f012808 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -1231,7 +1231,6 @@ static int hidpp_hrw_get_wheel_capability(struct hidpp_device *hidpp,
*multiplier = response.fap.params[0];
return 0;
return_default:
- *multiplier = 8;
hid_warn(hidpp->hid_dev,
"Couldn't get wheel multiplier (error %d), assuming %d.\n",
ret, *multiplier);
@@ -2696,7 +2695,7 @@ static int hi_res_scroll_look_up_microns(__u32 product_id)
static int hi_res_scroll_enable(struct hidpp_device *hidpp)
{
int ret;
- u8 multiplier;
+ u8 multiplier = 8;

if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2121) {
ret = hidpp_hrw_set_wheel_mode(hidpp, false, true, false);
@@ -2704,10 +2703,9 @@ static int hi_res_scroll_enable(struct hidpp_device *hidpp)
} else if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2120) {
ret = hidpp_hrs_set_highres_scrolling_mode(hidpp, true,
&multiplier);
- } else /* if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_1P0) */ {
+ } else /* if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_1P0) */
ret = hidpp10_enable_scrolling_acceleration(hidpp);
- multiplier = 8;
- }
+
if (ret)
return ret;

--
1.7.12.4

2018-09-21 01:49:01

by zhong jiang

Subject: Re: [PATCH v2] HID: logitech: fix a used uninitialized GCC warning

Hi Jiri

Can you pick up the patch?

Thanks
zhong jiang

On 2018/9/13 15:41, zhong jiang wrote:
> Fix the following compile warning:
>
> drivers/hid/hid-logitech-hidpp.c: In function 'hi_res_scroll_enable':
> drivers/hid/hid-logitech-hidpp.c:2714:54: warning: 'multiplier' may be used uninitialized in this function [-Wmaybe-uninitialized]
> hidpp->vertical_wheel_counter.resolution_multiplier = multiplier;
>
> Signed-off-by: zhong jiang <[email protected]>
> ---
> v1->v2:
> According to Benjamin's suggestion, To initialize the value
> and remove the duplicated assignement.
>
> drivers/hid/hid-logitech-hidpp.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
> index 5f0c080..f012808 100644
> --- a/drivers/hid/hid-logitech-hidpp.c
> +++ b/drivers/hid/hid-logitech-hidpp.c
> @@ -1231,7 +1231,6 @@ static int hidpp_hrw_get_wheel_capability(struct hidpp_device *hidpp,
> *multiplier = response.fap.params[0];
> return 0;
> return_default:
> - *multiplier = 8;
> hid_warn(hidpp->hid_dev,
> "Couldn't get wheel multiplier (error %d), assuming %d.\n",
> ret, *multiplier);
> @@ -2696,7 +2695,7 @@ static int hi_res_scroll_look_up_microns(__u32 product_id)
> static int hi_res_scroll_enable(struct hidpp_device *hidpp)
> {
> int ret;
> - u8 multiplier;
> + u8 multiplier = 8;
>
> if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2121) {
> ret = hidpp_hrw_set_wheel_mode(hidpp, false, true, false);
> @@ -2704,10 +2703,9 @@ static int hi_res_scroll_enable(struct hidpp_device *hidpp)
> } else if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2120) {
> ret = hidpp_hrs_set_highres_scrolling_mode(hidpp, true,
> &multiplier);
> - } else /* if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_1P0) */ {
> + } else /* if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_1P0) */
> ret = hidpp10_enable_scrolling_acceleration(hidpp);
> - multiplier = 8;
> - }
> +
> if (ret)
> return ret;
>

2018-09-24 09:32:10

by Jiri Kosina

Subject: Re: [PATCH v2] HID: logitech: fix a used uninitialized GCC warning

On Thu, 13 Sep 2018, zhong jiang wrote:

> Fix the following compile warning:
>
> drivers/hid/hid-logitech-hidpp.c: In function 'hi_res_scroll_enable':
> drivers/hid/hid-logitech-hidpp.c:2714:54: warning: 'multiplier' may be used uninitialized in this function [-Wmaybe-uninitialized]
> hidpp->vertical_wheel_counter.resolution_multiplier = multiplier;
>
> Signed-off-by: zhong jiang <[email protected]>
> ---
> v1->v2:
> According to Benjamin's suggestion, To initialize the value
> and remove the duplicated assignement.

Applied to for-4.20/logitech-highres. Thanks,

--
Jiri Kosina
SUSE Labs