Re: [PATCH V3 1/2] drm/vkms: Refactor vkms_composer_worker() to prep for virtual_hw mode

From: Sumera Priyadarsini
Date: Sun Apr 04 2021 - 13:51:14 EST

On Sun, Apr 4, 2021 at 9:19 PM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> Hi Sumera,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on linus/master]
> [also build test WARNING on v5.12-rc5 next-20210401]
> [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/Sumera-Priyadarsini/Add-virtual-hardware-module/20210404-211300
> base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2023a53bdf41b7646b1d384b6816af06309f73a5
> config: mips-randconfig-r025-20210404 (attached as .config)
> compiler: mipsel-linux-gcc (GCC) 9.3.0
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # https://github.com/0day-ci/linux/commit/4bd5c27357dd86b6099f3f28db5db722ceeed582
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Sumera-Priyadarsini/Add-virtual-hardware-module/20210404-211300
> git checkout 4bd5c27357dd86b6099f3f28db5db722ceeed582
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>):
>
> drivers/gpu/drm/vkms/vkms_composer.c: In function 'vkms_composer_worker':
> >> drivers/gpu/drm/vkms/vkms_composer.c:226:20: warning: variable 'wb_pending' set but not used [-Wunused-but-set-variable]
> 226 | bool crc_pending, wb_pending;
> | ^~~~~~~~~~
>
>
> vim +/wb_pending +226 drivers/gpu/drm/vkms/vkms_composer.c
>
> 4bd5c27357dd86 drivers/gpu/drm/vkms/vkms_composer.c Sumera Priyadarsini 2021-04-04 209
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 210 /**
> a4e7e98e90ebd9 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2019-06-25 211 * vkms_composer_worker - ordered work_struct to compute CRC
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 212 *
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 213 * @work: work_struct
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 214 *
> a4e7e98e90ebd9 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2019-06-25 215 * Work handler for composing and computing CRCs. work_struct scheduled in
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 216 * an ordered workqueue that's periodically scheduled to run by
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 217 * _vblank_handle() and flushed at vkms_atomic_crtc_destroy_state().
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 218 */
> a4e7e98e90ebd9 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2019-06-25 219 void vkms_composer_worker(struct work_struct *work)
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 220 {
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 221 struct vkms_crtc_state *crtc_state = container_of(work,
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 222 struct vkms_crtc_state,
> a4e7e98e90ebd9 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2019-06-25 223 composer_work);
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 224 struct drm_crtc *crtc = crtc_state->base.crtc;
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 225 struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
> dbd9d80c1b2e03 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2020-08-30 @226 bool crc_pending, wb_pending;
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 227 u64 frame_start, frame_end;
> 4bd5c27357dd86 drivers/gpu/drm/vkms/vkms_composer.c Sumera Priyadarsini 2021-04-04 228 u32 crc32 = 0;
> 953025763d1421 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2020-08-30 229 int ret;
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 230
> a4e7e98e90ebd9 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2019-06-25 231 spin_lock_irq(&out->composer_lock);
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 232 frame_start = crtc_state->frame_start;
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 233 frame_end = crtc_state->frame_end;
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 234 crc_pending = crtc_state->crc_pending;
> dbd9d80c1b2e03 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2020-08-30 235 wb_pending = crtc_state->wb_pending;
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 236 crtc_state->frame_start = 0;
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 237 crtc_state->frame_end = 0;
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 238 crtc_state->crc_pending = false;
> a4e7e98e90ebd9 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2019-06-25 239 spin_unlock_irq(&out->composer_lock);
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 240
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 241 /*
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 242 * We raced with the vblank hrtimer and previous work already computed
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 243 * the crc, nothing to do.
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 244 */
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 245 if (!crc_pending)
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 246 return;
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 247
> 4bd5c27357dd86 drivers/gpu/drm/vkms/vkms_composer.c Sumera Priyadarsini 2021-04-04 248 ret = vkms_composer_common(crtc_state, out, crtc_state->wb_pending, &crc32);
> 4bd5c27357dd86 drivers/gpu/drm/vkms/vkms_composer.c Sumera Priyadarsini 2021-04-04 249 if (ret == -EINVAL)
> 953025763d1421 drivers/gpu/drm/vkms/vkms_composer.c Rodrigo Siqueira 2020-08-30 250 return;
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 251 /*
> 18d0952a838ba5 drivers/gpu/drm/vkms/vkms_crc.c Daniel Vetter 2019-06-07 252 * The worker can fall behind the vblank hrtimer, make sure we catch up.
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 253 */
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 254 while (frame_start <= frame_end)
> 0ca33adb91c0a9 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-09-04 255 drm_crtc_add_crc_entry(crtc, true, frame_start++, &crc32);
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 256 }
> 6c234fe37c5762 drivers/gpu/drm/vkms/vkms_crc.c Haneen Mohammed 2018-08-02 257
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

This error seems to have creeped in again. I am not sure why I didn't
get any warning for this.
I will submit a revised patch, sorry for the noise. :/