On Tue, Oct 18, 2022 at 04:50:41PM -0500, Dan Vacura wrote: > Some UDC hw may not support skipping interrupts, but still support the > request. Allow the interrupt frequency to be configurable to the user. > > Signed-off-by: Dan Vacura <w36195@xxxxxxxxxxxx> > --- > V1 -> V2: > - no change, new patch in series > V2 -> V3: > - default to baseline value of 4, fix storing the initial value > V3 -> V4: > - no change > > Documentation/ABI/testing/configfs-usb-gadget-uvc | 1 + > Documentation/usb/gadget-testing.rst | 2 ++ Adding more tunable knobs always just adds complexity and fragility as things do not get tested. Can't we just make this dynamic and work properly on all systems? What UDC hardware types do not allow skipping interrupts? Why can't we just detect that and only do that if this is the case or not? > drivers/usb/gadget/function/f_uvc.c | 3 +++ > drivers/usb/gadget/function/u_uvc.h | 1 + > drivers/usb/gadget/function/uvc.h | 2 ++ > drivers/usb/gadget/function/uvc_configfs.c | 2 ++ > drivers/usb/gadget/function/uvc_queue.c | 6 ++++++ > drivers/usb/gadget/function/uvc_video.c | 3 ++- > 8 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc > index 611b23e6488d..5dfaa3f7f6a4 100644 > --- a/Documentation/ABI/testing/configfs-usb-gadget-uvc > +++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc > @@ -8,6 +8,7 @@ Description: UVC function directory > streaming_maxpacket 1..1023 (fs), 1..3072 (hs/ss) > streaming_interval 1..16 > function_name string [32] > + req_int_skip_div unsigned int > =================== ============================= > > What: /config/usb-gadget/gadget/functions/uvc.name/control > diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst > index 2278c9ffb74a..f9b5a09be1f4 100644 > --- a/Documentation/usb/gadget-testing.rst > +++ b/Documentation/usb/gadget-testing.rst > @@ -794,6 +794,8 @@ The uvc function provides these attributes in its function directory: > sending or receiving when this configuration is > selected > function_name name of the interface > + req_int_skip_div divisor of total requests to aid in calculating > + interrupt frequency, 0 indicates all interrupt This provides no information that would help to determine how to configure this at all. I wouldn't know what to do with this, so that's a huge sign that this is not a good interface :( thanks, greg k-h
