Hi Hans On Sun, Jan 28, 2024 at 09:58:41PM +0100, Hans de Goede wrote: > Hi All, > > While adding vblank ctrl support to the ov2680 driver I was looking > at the vblank ctrl code in the ov5693 and I noticed something > which I believe is weird / undesirable. > > When setting a new mode the ov5693 driver does not keep the current > vts value (adjusting vblank to keep vts and thus the framerare and > exposure unchanged). > > Instead it calculates a new vts value, resetting the framerate > to 30 fps; or 60 fps for smaller resolutions and then sets > vblank to the new (vts - new_mode->height) and adjusts > the exposure control-range to fit within the new vts, potentially > also changing the exposure value. > > This behavior of the ov5693 code means that switching resolution > also changes the framerate and the exposure value which seems > undesirable. > > The vblank and hblank control values changes on setting a mode > is unavoidable but the framerate and exposure value changing > at the same time seems undesirable. > > Note that this also halves the max supported exposure value > when going to a lower-res mode even when userspace never > touches the vblank control. > Would you be interested in reviewing https://patchwork.kernel.org/project/linux-media/list/?series=697777&state=%2A&archive=both and discuss there what the desired behaviour should be ? > Regards, > > Hans > > > > >
