Hi Hans On Tue, Nov 12, 2024 at 9:41 AM Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > > This supersedes (1). > > The first patch fixes the tegra-video driver: it now creates the new > controls for the control handler first, before calling v4l2_ctrl_add_handler(). > > This prevents a warning, which is introduced in the next patch. > > The second patch checks for adding a duplicate control to the same handler, > and returns an error, but it also adds a warning if new controls are added > to a handler after v4l2_ctrl_add_handler() is called. In the uvc driver, users can create controls with the ioct UVCIOC_CTRL_MAP https://docs.kernel.org/userspace-api/media/drivers/uvcvideo.html I guess that would be the equivalent of adding controls after v4l2_ctrl_add_handler() Right now, uvc does not use the control framework, but I would like to dream about a world where this is possible :) Is there a chance that you consider that usecase? Regards! > > Eventually this sequence should result in an error instead of a warning, > but I feel it is better to keep the warning for a few kernel cycles > to make sure any broken driver is fixed. > > From my analysis it is only the tegra-video driver that has this issue, > but I may have missed a corner case somewhere. > > Regards, > > Hans > > 1: https://patchwork.linuxtv.org/project/linux-media/patch/ddb6e006-7440-41c5-8aaa-685b058418b4@xxxxxxxxx/ > > Hans Verkuil (2): > media: staging: tegra-video: postpone v4l2_ctrl_add_handler > media: v4l2-core: v4l2-ctrls: check for handler_new_ref misuse > > drivers/media/v4l2-core/v4l2-ctrls-core.c | 46 ++++++++++++++++++++--- > drivers/staging/media/tegra-video/vi.c | 11 +++--- > include/media/v4l2-ctrls.h | 5 +++ > 3 files changed, 50 insertions(+), 12 deletions(-) > > -- > 2.45.2 > > -- Ricardo Ribalda
