Re: [PATCH v7 2/8] media: uvcvideo: Add support for per-device control mapping overrides

From: Ricardo Ribalda
Date: Thu Jun 30 2022 - 19:17:02 EST


Hi Dan

Thanks for your mail

On Thu, 30 Jun 2022 at 13:08, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> Hi Ricardo,
>
> url: https://github.com/intel-lab-lkp/linux/commits/Ricardo-Ribalda/uvcvideo-Fix-handling-of-power_line_frequency/20220617-185644
> base: git://linuxtv.org/media_tree.git master
> config: microblaze-randconfig-m031-20220629 (https://download.01.org/0day-ci/archive/20220630/202206301144.r7yv0yk2-lkp@xxxxxxxxx/config)
> compiler: microblaze-linux-gcc (GCC) 11.3.0
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> smatch warnings:
> drivers/media/usb/uvc/uvc_ctrl.c:2459 uvc_ctrl_init_ctrl() error: uninitialized symbol 'mapping'.
>
> vim +/mapping +2459 drivers/media/usb/uvc/uvc_ctrl.c
>
> 866c6bdd5663d4 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2021-06-18 2401 static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
> 866c6bdd5663d4 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2021-06-18 2402 struct uvc_control *ctrl)
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2403 {
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2404 const struct uvc_control_info *info = uvc_ctrls;
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2405 const struct uvc_control_info *iend = info + ARRAY_SIZE(uvc_ctrls);
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2406 const struct uvc_control_mapping *mapping;
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2407 const struct uvc_control_mapping *mend;
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2408
> 52c58ad6f95ff6 drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2409 /* XU controls initialization requires querying the device for control
> 52c58ad6f95ff6 drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2410 * information. As some buggy UVC devices will crash when queried
> 52c58ad6f95ff6 drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2411 * repeatedly in a tight loop, delay XU controls initialization until
> 52c58ad6f95ff6 drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2412 * first use.
> 52c58ad6f95ff6 drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2413 */
> 52c58ad6f95ff6 drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2414 if (UVC_ENTITY_TYPE(ctrl->entity) == UVC_VC_EXTENSION_UNIT)
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2415 return;
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2416
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2417 for (; info < iend; ++info) {
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2418 if (uvc_entity_match_guid(ctrl->entity, info->entity) &&
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2419 ctrl->index == info->index) {
> 866c6bdd5663d4 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2021-06-18 2420 uvc_ctrl_add_info(chain->dev, ctrl, info);
> 93df48d37c3f03 drivers/media/usb/uvc/uvc_ctrl.c Hans de Goede 2020-07-28 2421 /*
> 93df48d37c3f03 drivers/media/usb/uvc/uvc_ctrl.c Hans de Goede 2020-07-28 2422 * Retrieve control flags from the device. Ignore errors
> 93df48d37c3f03 drivers/media/usb/uvc/uvc_ctrl.c Hans de Goede 2020-07-28 2423 * and work with default flag values from the uvc_ctrl
> 93df48d37c3f03 drivers/media/usb/uvc/uvc_ctrl.c Hans de Goede 2020-07-28 2424 * array when the device doesn't properly implement
> 93df48d37c3f03 drivers/media/usb/uvc/uvc_ctrl.c Hans de Goede 2020-07-28 2425 * GET_INFO on standard controls.
> 93df48d37c3f03 drivers/media/usb/uvc/uvc_ctrl.c Hans de Goede 2020-07-28 2426 */
> 866c6bdd5663d4 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2021-06-18 2427 uvc_ctrl_get_flags(chain->dev, ctrl, &ctrl->info);
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2428 break;
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2429 }
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2430 }
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2431
> 071c8bb827c80a drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2432 if (!ctrl->initialized)
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2433 return;
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2434
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2435 /*
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2436 * First check if the device provides a custom mapping for this control,
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2437 * used to override standard mappings for non-conformant devices. Don't
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2438 * process standard mappings if a custom mapping is found. This
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2439 * mechanism doesn't support combining standard and custom mappings for
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2440 * a single control.
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2441 */
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2442 if (chain->dev->info->mappings) {
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2443 bool custom = false;
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2444 unsigned int i;
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2445
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2446 for (i = 0; (mapping = chain->dev->info->mappings[i]); ++i) {
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2447 if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2448 ctrl->info.selector == mapping->selector) {
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2449 __uvc_ctrl_add_mapping(chain, ctrl, mapping);
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2450 custom = true;
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2451 }
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2452 }
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2453
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2454 if (custom)
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2455 return;
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2456 }
>
> "mapping" uninitialized if chain->dev->info->mappings is NULL.
>
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2457
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2458 /* Process common mappings next. */
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 @2459 mend = mapping + ARRAY_SIZE(uvc_ctrl_mappings);
> ^^^^^^^
>
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2460 for (mapping = uvc_ctrl_mappings; mapping < mend; ++mapping) {
>
> I'm surprised this made it through testing... Anyway, the easier way to
> to iterate through an array of structs is just say:

There is already a new version under review that fixes this:

https://patchwork.linuxtv.org/project/linux-media/patch/20220617235610.321917-3-ribalda@xxxxxxxxxxxx/


>
> for (i = 0; i < ARRAY_SIZE(uvc_ctrl_mappings); i++) {
> mapping = &uvc_ctrl_mappings[i];
>

I agree, and that is what I normally used, but that driver iterate this way...

Thanks again!

PS: Any idea why the test was triggered 14+ days after the patch was sent?

> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2461 if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2462 ctrl->info.selector == mapping->selector)
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2463 __uvc_ctrl_add_mapping(chain, ctrl, mapping);
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2464 }
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2465
> 10bdca4191d7a8 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2466 /* Finally process version-specific mappings. */
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2467 if (chain->dev->uvc_version < 0x0150) {
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2468 mapping = uvc_ctrl_mappings_uvc11;
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2469 mend = mapping + ARRAY_SIZE(uvc_ctrl_mappings_uvc11);
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2470 } else {
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2471 mapping = uvc_ctrl_mappings_uvc15;
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2472 mend = mapping + ARRAY_SIZE(uvc_ctrl_mappings_uvc15);
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2473 }
> 87c205087585a0 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2022-06-17 2474
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2475 for (; mapping < mend; ++mapping) {
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2476 if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
> 071c8bb827c80a drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-29 2477 ctrl->info.selector == mapping->selector)
> 866c6bdd5663d4 drivers/media/usb/uvc/uvc_ctrl.c Ricardo Ribalda 2021-06-18 2478 __uvc_ctrl_add_mapping(chain, ctrl, mapping);
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2479 }
> ba2fa99668bb9b drivers/media/video/uvc/uvc_ctrl.c Laurent Pinchart 2010-09-20 2480 }
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
>


--
Ricardo Ribalda