Hi Laurent, On Sun, Jun 07, 2020 at 05:41:58AM +0300, Laurent Pinchart wrote: > Note that the CMM driver is controlled by the DU driver. As the DU > driver will reenable the display during resume, it will call > rcar_du_cmm_setup() at resume time, which will reprogram the CMM. There > should thus be no need for manual suspend/resume handling in the CMM as > far as I can tell, but we need to ensure that the CMM is suspended > before and resumed after the DU. I believe this could be implemented > using device links. Based on below quote [*] from Jacopo's commit [**], isn't the device link relationship already in place? [*] Quote from commit [**] Enforce the probe and suspend/resume ordering of DU and CMM by creating a stateless device link between the two. [**] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8de707aeb45241 ("drm: rcar-du: kms: Initialize CMM instances") -- Best regards, Eugeniu Rosca
