Hello Eugeniu, sorry for the late reply On Wed, May 27, 2020 at 09:15:55AM +0200, Eugeniu Rosca wrote: > Hi Jacopo, > > On Tue, Oct 15, 2019 at 12:46:13PM +0200, Jacopo Mondi wrote: > ----8<--- > > > * Testing > > I have tested by injecting a color inversion LUT table and enabling/disabling it > > every 50 displayed frames: > > https://jmondi.org/cgit/kmsxx/log/?h=gamma_lut > > Could you kindly share the cross compilation steps for your kmsxx fork? > I usually build it on the target :) > Just out of curiosity, have you ever tried to pull the display's HDMI > cable while reading from CM2_LUT_TBL? Ahem, not really :) Did I get you right, you mean disconnecting the HDMI cable from the board ? > > At least with the out-of-tree CMM implementation [*], this sends the > R-Car3 reference targets into an unrecoverable freeze, with no lockup > reported by the kernel (i.e. looks like an serious HW issue). > > > > > CMM functionalities are retained between suspend/resume cycles (tested with > > suspend-to-idle) without requiring a re-programming of the LUT tables. > > Hmm. Is this backed up by any statement in the HW User's manual? > This comes in contrast with the original Renesas CMM implementation [**] > which does make use of suspend (where the freeze actually happens). > > Can we infer, based on your statement, that we could also get rid of > the suspend callback in [**]? As Geert (thanks) explained what I've tested with is suspend-to-idle, which retains the state of the LUT tables (and I assume other not-yet-implemented CMM features, like CLU). I recall the out-of-tree driver has suspend/resume routines but I never really tested that. Thanks j > > [*] https://github.com/renesas-rcar/du_cmm > [**] https://github.com/renesas-rcar/du_cmm/blob/c393ed49834bdbc/meta-rcar-gen3/recipes-kernel/linux/linux-renesas/0001-drm-rcar-du-Add-DU-CMM-support.patch#L1912 > > -- > Best regards, > Eugeniu Rosca
