Hi Dan, Thank you for the series. On Tue, Dec 13, 2022 at 08:37:30AM +0000, Daniel Scally wrote: > The current UVC gadget implementation hardcodes a single color matching > descriptor and transmits it a single time following all the format and frame I'm not sure I would use "transmits" in this context. Descriptors are for sure transmitted over the wire, but all in one go, not as individual units (at least within a configuration descriptor). Maybe "includes" would be a better term ? This is nitpicking for the cover letter, but the comment applies more importantly to commit messages and code for the whole series. > descriptors. This is inflexible, and additionally applies only to the _last_ > format in the array of descriptors. > > This series extends the support such that the default descriptor can be amended > and is transmitted once-per-format instead of once-only, it then adds the ability > to create new color matching descriptors and associate them with particular formats. > The default color matching descriptor is retained and used where the user does not > link a new color matching descriptor to the format, so the default interaction > with userspace is unchanged from the current implementation. I wonder if we shouldn't drop the default descriptor. If userspace doesn't specify one, then we really can't know what colorimetry data applies to the frames. Instead of providing a default to the host, not providing any colorimetry information would be better. > Daniel Scally (6): > usb: gadget: usb: Remove "default" from color matching attributes > usb: gadget: uvc: Add struct for color matching in configs > usb: gadget: uvc: Copy color matching descriptor for each frame > usb: gadget: uvc: Remove the hardcoded default color matching > usb: gadget: uvc: Make color matching attributes read/write > usb: gadget: uvc: Allow creating new color matching descriptors > > .../ABI/testing/configfs-usb-gadget-uvc | 6 +- > drivers/usb/gadget/function/f_uvc.c | 9 - > drivers/usb/gadget/function/u_uvc.h | 1 - > drivers/usb/gadget/function/uvc_configfs.c | 247 +++++++++++++++--- > drivers/usb/gadget/function/uvc_configfs.h | 9 + > 5 files changed, 228 insertions(+), 44 deletions(-) -- Regards, Laurent Pinchart
