Hi chenchangcheng, kernel test robot noticed the following build warnings: [auto build test WARNING on 4701f33a10702d5fc577c32434eb62adde0a1ae1] url: https://github.com/intel-lab-lkp/linux/commits/chenchangcheng/media-uvcvideo-Fix-bandwidth-issue-for-Alcor-camera/20250318-165843 base: 4701f33a10702d5fc577c32434eb62adde0a1ae1 patch link: https://lore.kernel.org/r/20250318085724.1151547-1-ccc194101%40163.com patch subject: [PATCH v2] media: uvcvideo: Fix bandwidth issue for Alcor camera config: i386-buildonly-randconfig-006-20250319 (https://download.01.org/0day-ci/archive/20250319/202503191124.azEOPRHh-lkp@xxxxxxxxx/config) compiler: clang version 20.1.0 (https://github.com/llvm/llvm-project 24a30daaa559829ad079f2ff7f73eb4e18095f88) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250319/202503191124.azEOPRHh-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202503191124.azEOPRHh-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): drivers/media/usb/uvc/uvc_video.c:269:3: error: call to undeclared function 'uvc_printk'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 269 | uvc_printk(KERN_WARNING, "the max payload transmission size [%d] | ^ >> drivers/media/usb/uvc/uvc_video.c:269:28: warning: missing terminating '"' character [-Winvalid-pp-token] 269 | uvc_printk(KERN_WARNING, "the max payload transmission size [%d] | ^ drivers/media/usb/uvc/uvc_video.c:269:28: error: expected expression drivers/media/usb/uvc/uvc_video.c:271:45: warning: missing terminating '"' character [-Winvalid-pp-token] 271 | use the default value of 1024 bytes.\n", | ^ 2 warnings and 2 errors generated. vim +269 drivers/media/usb/uvc/uvc_video.c 162 163 static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, 164 struct uvc_streaming_control *ctrl) 165 { 166 const struct uvc_format *format = NULL; 167 const struct uvc_frame *frame = NULL; 168 unsigned int i; 169 170 /* 171 * The response of the Elgato Cam Link 4K is incorrect: The second byte 172 * contains bFormatIndex (instead of being the second byte of bmHint). 173 * The first byte is always zero. The third byte is always 1. 174 * 175 * The UVC 1.5 class specification defines the first five bits in the 176 * bmHint bitfield. The remaining bits are reserved and should be zero. 177 * Therefore a valid bmHint will be less than 32. 178 * 179 * Latest Elgato Cam Link 4K firmware as of 2021-03-23 needs this fix. 180 * MCU: 20.02.19, FPGA: 67 181 */ 182 if (usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k) && 183 ctrl->bmHint > 255) { 184 u8 corrected_format_index = ctrl->bmHint >> 8; 185 186 uvc_dbg(stream->dev, VIDEO, 187 "Correct USB video probe response from {bmHint: 0x%04x, bFormatIndex: %u} to {bmHint: 0x%04x, bFormatIndex: %u}\n", 188 ctrl->bmHint, ctrl->bFormatIndex, 189 1, corrected_format_index); 190 ctrl->bmHint = 1; 191 ctrl->bFormatIndex = corrected_format_index; 192 } 193 194 for (i = 0; i < stream->nformats; ++i) { 195 if (stream->formats[i].index == ctrl->bFormatIndex) { 196 format = &stream->formats[i]; 197 break; 198 } 199 } 200 201 if (format == NULL) 202 return; 203 204 for (i = 0; i < format->nframes; ++i) { 205 if (format->frames[i].bFrameIndex == ctrl->bFrameIndex) { 206 frame = &format->frames[i]; 207 break; 208 } 209 } 210 211 if (frame == NULL) 212 return; 213 214 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) || 215 (ctrl->dwMaxVideoFrameSize == 0 && 216 stream->dev->uvc_version < 0x0110)) 217 ctrl->dwMaxVideoFrameSize = 218 frame->dwMaxVideoFrameBufferSize; 219 220 /* 221 * The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to 222 * compute the bandwidth on 16 bits and erroneously sign-extend it to 223 * 32 bits, resulting in a huge bandwidth value. Detect and fix that 224 * condition by setting the 16 MSBs to 0 when they're all equal to 1. 225 */ 226 if ((ctrl->dwMaxPayloadTransferSize & 0xffff0000) == 0xffff0000) 227 ctrl->dwMaxPayloadTransferSize &= ~0xffff0000; 228 229 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) && 230 stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH && 231 stream->intf->num_altsetting > 1) { 232 u32 interval; 233 u32 bandwidth; 234 235 interval = (ctrl->dwFrameInterval > 100000) 236 ? ctrl->dwFrameInterval 237 : frame->dwFrameInterval[0]; 238 239 /* 240 * Compute a bandwidth estimation by multiplying the frame 241 * size by the number of video frames per second, divide the 242 * result by the number of USB frames (or micro-frames for 243 * high- and super-speed devices) per second and add the UVC 244 * header size (assumed to be 12 bytes long). 245 */ 246 bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; 247 bandwidth *= 10000000 / interval + 1; 248 bandwidth /= 1000; 249 if (stream->dev->udev->speed >= USB_SPEED_HIGH) 250 bandwidth /= 8; 251 bandwidth += 12; 252 253 /* 254 * The bandwidth estimate is too low for many cameras. Don't use 255 * maximum packet sizes lower than 1024 bytes to try and work 256 * around the problem. According to measurements done on two 257 * different camera models, the value is high enough to get most 258 * resolutions working while not preventing two simultaneous 259 * VGA streams at 15 fps. 260 */ 261 bandwidth = max_t(u32, bandwidth, 1024); 262 263 ctrl->dwMaxPayloadTransferSize = bandwidth; 264 } 265 266 if (format->flags & UVC_FMT_FLAG_COMPRESSED && 267 stream->dev->quirks & UVC_QUIRK_OVERFLOW_BANDWIDTH && 268 ctrl->dwMaxPayloadTransferSize > stream->maxpsize) { > 269 uvc_printk(KERN_WARNING, "the max payload transmission size [%d] 270 exceededs the size of the ep max packet. 271 use the default value of 1024 bytes.\n", 272 ctrl->dwMaxPayloadTransferSize); 273 ctrl->dwMaxPayloadTransferSize = 1024; 274 } 275 } 276 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
