Hi Michael, I love your patch! Yet something to improve: [auto build test ERROR on media-tree/master] [also build test ERROR on usb/usb-testing v5.16-rc4 next-20211206] [cannot apply to balbi-usb/testing/next peter-chen-usb/for-usb-next] [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/Michael-Grzeschik/usb-gadget-uvc-use-configfs-entries-for-negotiation-and-v4l2-VIDIOCS/20211206-070014 base: git://linuxtv.org/media_tree.git master config: riscv-randconfig-r024-20211205 (https://download.01.org/0day-ci/archive/20211206/202112062124.HEJZJ0fR-lkp@intel.com/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 6e8678903523019903222e4521a5e41af743cab0) 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 # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://github.com/0day-ci/linux/commit/8fdc5cd9a8845e9a061b42155d8d05ddb8514921 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Michael-Grzeschik/usb-gadget-uvc-use-configfs-entries-for-negotiation-and-v4l2-VIDIOCS/20211206-070014 git checkout 8fdc5cd9a8845e9a061b42155d8d05ddb8514921 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/usb/gadget/function/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): drivers/usb/gadget/function/uvc_v4l2.c:73:2: warning: variable 'uformat' is used uninitialized whenever 'for' loop exits because its condition is false [-Wsometimes-uninitialized] list_for_each_entry(format, &uvc->header->formats, entry) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/list.h:631:7: note: expanded from macro 'list_for_each_entry' !list_entry_is_head(pos, head, member); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/usb/gadget/function/uvc_v4l2.c:81:9: note: uninitialized use occurs here return uformat; ^~~~~~~ drivers/usb/gadget/function/uvc_v4l2.c:73:2: note: remove the condition if it is always true list_for_each_entry(format, &uvc->header->formats, entry) { ^ include/linux/list.h:631:7: note: expanded from macro 'list_for_each_entry' !list_entry_is_head(pos, head, member); \ ^ drivers/usb/gadget/function/uvc_v4l2.c:70:29: note: initialize the variable 'uformat' to silence this warning struct uvcg_format *uformat; ^ = NULL drivers/usb/gadget/function/uvc_v4l2.c:139:2: warning: variable 'uformat' is used uninitialized whenever 'for' loop exits because its condition is false [-Wsometimes-uninitialized] list_for_each_entry(format, &uvc->header->formats, entry) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/list.h:631:7: note: expanded from macro 'list_for_each_entry' !list_entry_is_head(pos, head, member); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/usb/gadget/function/uvc_v4l2.c:148:9: note: uninitialized use occurs here return uformat; ^~~~~~~ drivers/usb/gadget/function/uvc_v4l2.c:139:2: note: remove the condition if it is always true list_for_each_entry(format, &uvc->header->formats, entry) { ^ include/linux/list.h:631:7: note: expanded from macro 'list_for_each_entry' !list_entry_is_head(pos, head, member); \ ^ drivers/usb/gadget/function/uvc_v4l2.c:137:29: note: initialize the variable 'uformat' to silence this warning struct uvcg_format *uformat; ^ = NULL >> drivers/usb/gadget/function/uvc_v4l2.c:334:14: error: use of undeclared identifier 'video' spin_lock(&video->frame_lock); ^ drivers/usb/gadget/function/uvc_v4l2.c:339:16: error: use of undeclared identifier 'video' spin_unlock(&video->frame_lock); ^ 2 warnings and 2 errors generated. vim +/video +334 drivers/usb/gadget/function/uvc_v4l2.c 305 306 static int 307 uvc_v4l2_enum_frameintervals(struct file *file, void *fh, 308 struct v4l2_frmivalenum *fival) 309 { 310 struct video_device *vdev = video_devdata(file); 311 struct uvc_device *uvc = video_get_drvdata(vdev); 312 struct uvcg_format *uformat = NULL; 313 struct uvcg_frame *uframe = NULL; 314 struct uvcg_frame_ptr *frame; 315 316 uformat = find_format_by_pix(uvc, fival->pixel_format); 317 if (!uformat) 318 return -EINVAL; 319 320 list_for_each_entry(frame, &uformat->frames, entry) { 321 if (frame->frm->frame.w_width == fival->width && 322 frame->frm->frame.w_height == fival->height) { 323 uframe = frame->frm; 324 break; 325 } 326 } 327 if (!uframe) 328 return -EINVAL; 329 330 if (uvc->streamon) { 331 if (fival->index >= 1) 332 return -EINVAL; 333 > 334 spin_lock(&video->frame_lock); 335 336 fival->discrete.numerator = 337 uframe->dw_frame_interval[uvc->video.cur_ival - 1]; 338 339 spin_unlock(&video->frame_lock); 340 } else { 341 if (fival->index >= uframe->frame.b_frame_interval_type) 342 return -EINVAL; 343 344 fival->discrete.numerator = 345 uframe->dw_frame_interval[fival->index]; 346 } 347 348 /* TODO: handle V4L2_FRMIVAL_TYPE_STEPWISE */ 349 fival->type = V4L2_FRMIVAL_TYPE_DISCRETE; 350 fival->discrete.denominator = 10000000; 351 v4l2_simplify_fraction(&fival->discrete.numerator, 352 &fival->discrete.denominator, 8, 333); 353 354 return 0; 355 } 356 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org