| Message ID | 20170328100321.3836826-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Arnd,
[auto build test ERROR on staging/staging-testing]
[also build test ERROR on next-20170328]
[cannot apply to linuxtv-media/master v4.11-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Arnd-Bergmann/staging-atomisp-avoid-false-positive-maybe-uninitialized-warning/20170329-023715
config: i386-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
drivers/staging/media/atomisp/i2c/mt9m114.c: In function 'mt9m114_get_fmt':
>> drivers/staging/media/atomisp/i2c/mt9m114.c:818:25: error: unused variable 'dev' [-Werror=unused-variable]
struct mt9m114_device *dev = to_mt9m114_sensor(sd);
^~~
drivers/staging/media/atomisp/i2c/mt9m114.c: In function 'mt9m114_s_exposure_selection':
drivers/staging/media/atomisp/i2c/mt9m114.c:1179:25: error: unused variable 'dev' [-Werror=unused-variable]
struct mt9m114_device *dev = to_mt9m114_sensor(sd);
^~~
cc1: all warnings being treated as errors
vim +/dev +818 drivers/staging/media/atomisp/i2c/mt9m114.c
a49d2536 Alan Cox 2017-02-17 812
a49d2536 Alan Cox 2017-02-17 813 static int mt9m114_get_fmt(struct v4l2_subdev *sd,
a49d2536 Alan Cox 2017-02-17 814 struct v4l2_subdev_pad_config *cfg,
a49d2536 Alan Cox 2017-02-17 815 struct v4l2_subdev_format *format)
a49d2536 Alan Cox 2017-02-17 816 {
a49d2536 Alan Cox 2017-02-17 817 struct v4l2_mbus_framefmt *fmt = &format->format;
a49d2536 Alan Cox 2017-02-17 @818 struct mt9m114_device *dev = to_mt9m114_sensor(sd);
a49d2536 Alan Cox 2017-02-17 819 int width, height;
a49d2536 Alan Cox 2017-02-17 820 int ret;
a49d2536 Alan Cox 2017-02-17 821 if (format->pad)
:::::: The code at line 818 was first introduced by commit
:::::: a49d25364dfb9f8a64037488a39ab1f56c5fa419 staging/atomisp: Add support for the Intel IPU v2
:::::: TO: Alan Cox <alan@linux.intel.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Tue, Mar 28, 2017 at 10:10 PM, kbuild test robot <lkp@intel.com> wrote: > Hi Arnd, > > [auto build test ERROR on staging/staging-testing] > [also build test ERROR on next-20170328] > [cannot apply to linuxtv-media/master v4.11-rc4] > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] > > url: https://github.com/0day-ci/linux/commits/Arnd-Bergmann/staging-atomisp-avoid-false-positive-maybe-uninitialized-warning/20170329-023715 > config: i386-allmodconfig (attached as .config) > compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 > reproduce: > # save the attached .config to linux build tree > make ARCH=i386 > > All errors (new ones prefixed by >>): > > drivers/staging/media/atomisp/i2c/mt9m114.c: In function 'mt9m114_get_fmt': >>> drivers/staging/media/atomisp/i2c/mt9m114.c:818:25: error: unused variable 'dev' [-Werror=unused-variable] > struct mt9m114_device *dev = to_mt9m114_sensor(sd); > ^~~ > drivers/staging/media/atomisp/i2c/mt9m114.c: In function 'mt9m114_s_exposure_selection': > drivers/staging/media/atomisp/i2c/mt9m114.c:1179:25: error: unused variable 'dev' [-Werror=unused-variable] > struct mt9m114_device *dev = to_mt9m114_sensor(sd); > ^~~ > cc1: all warnings being treated as errors > Very odd, I should obviouly have run into these when verifying my patch. I guess I'm preparing an v2 patch and will send that once I've built some more randconfigs on top of recreating the bug and fix. Arnd
diff --git a/drivers/staging/media/atomisp/i2c/mt9m114.c b/drivers/staging/media/atomisp/i2c/mt9m114.c index c4f4c888a59a..12b19fbafb5c 100644 --- a/drivers/staging/media/atomisp/i2c/mt9m114.c +++ b/drivers/staging/media/atomisp/i2c/mt9m114.c @@ -689,12 +689,13 @@ static struct mt9m114_res_struct *mt9m114_to_res(u32 w, u32 h) return &mt9m114_res[index]; } -static int mt9m114_res2size(unsigned int res, int *h_size, int *v_size) +static int mt9m114_res2size(struct v4l2_subdev *sd, int *h_size, int *v_size) { + struct mt9m114_device *dev = to_mt9m114_sensor(sd); unsigned short hsize; unsigned short vsize; - switch (res) { + switch (dev->res) { case MT9M114_RES_736P: hsize = MT9M114_RES_736P_SIZE_H; vsize = MT9M114_RES_736P_SIZE_V; @@ -708,7 +709,8 @@ static int mt9m114_res2size(unsigned int res, int *h_size, int *v_size) vsize = MT9M114_RES_960P_SIZE_V; break; default: - WARN(1, "%s: Resolution 0x%08x unknown\n", __func__, res); + v4l2_err(sd, "%s: Resolution 0x%08x unknown\n", __func__, + dev->res); return -EINVAL; } @@ -820,7 +822,7 @@ static int mt9m114_get_fmt(struct v4l2_subdev *sd, return -EINVAL; fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10; - ret = mt9m114_res2size(dev->res, &width, &height); + ret = mt9m114_res2size(sd, &width, &height); if (ret) return ret; fmt->width = width; @@ -1192,7 +1194,7 @@ static int mt9m114_s_exposure_selection(struct v4l2_subdev *sd, grid_right = sel->r.left + sel->r.width - 1; grid_bottom = sel->r.top + sel->r.height - 1; - ret = mt9m114_res2size(dev->res, &width, &height); + ret = mt9m114_res2size(sd, &width, &height); if (ret) return ret;
In combination with CONFIG_PROFILE_ANNOTATED_BRANCHES=y, the unlikely() inside of the WARN() macro becomes too complex for gcc to see that we don't use the output arguments of mt9m114_to_res() are used correctly: drivers/staging/media/atomisp/i2c/mt9m114.c: In function 'mt9m114_get_fmt': drivers/staging/media/atomisp/i2c/mt9m114.c:817:13: error: 'height' may be used uninitialized in this function [-Werror=maybe-uninitialized] int width, height; ^~~~~~ drivers/staging/media/atomisp/i2c/mt9m114.c: In function 'mt9m114_s_exposure_selection': drivers/staging/media/atomisp/i2c/mt9m114.c:1179:13: error: 'height' may be used uninitialized in this function [-Werror=maybe-uninitialized] Without WARN_ON(), there is no problem, so by simply replacing it with v4l2_err(), the warnings go away. The WARN() output is also not needed here, as we'd probably catch the problem before even getting here, and other checks for the same condition already use v4l2_err. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/staging/media/atomisp/i2c/mt9m114.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)