Re: [PATCH v3] backlight: lp855x: Switch to atomic PWM API

From: kernel test robot
Date: Sat Oct 30 2021 - 19:44:21 EST


Hi "Maíra,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on lee-backlight/for-backlight-next]
[also build test ERROR on v5.15-rc7 next-20211029]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Ma-ra-Canal/backlight-lp855x-Switch-to-atomic-PWM-API/20211030-213551
base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git for-backlight-next
config: i386-randconfig-a002-20211031 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/f4d53f4d51c78636fc4fd34aecbdcbd1f83f656e
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Ma-ra-Canal/backlight-lp855x-Switch-to-atomic-PWM-API/20211030-213551
git checkout f4d53f4d51c78636fc4fd34aecbdcbd1f83f656e
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

ld: drivers/video/backlight/lp855x_bl.o: in function `lp855x_pwm_ctrl':
>> drivers/video/backlight/lp855x_bl.c:253: undefined reference to `__udivdi3'


vim +253 drivers/video/backlight/lp855x_bl.c

233
234 static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
235 {
236 struct pwm_device *pwm = NULL;
237 struct pwm_state state;
238
239 /* request pwm device with the consumer name */
240 if (!lp->pwm) {
241 pwm = devm_pwm_get(lp->dev, lp->chipname);
242 if (IS_ERR(pwm))
243 return;
244
245 lp->pwm = pwm;
246
247 pwm_init_state(lp->pwm, &state);
248 state.period = lp->pdata->period_ns;
249 }
250
251 pwm_get_state(lp->pwm, &state);
252
> 253 state.duty_cycle = br * state.period / max_br;
254 state.enabled = state.duty_cycle;
255
256 pwm_apply_state(lp->pwm, &state);
257 }
258

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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