Messages in this thread | | | From | Gotthard Voellmeke <> | Subject | RE: [PATCH v5 0/8] drm: rcar-du: Add Color Management Module (CMM) | Date | Wed, 27 May 2020 07:40:14 +0000 |
| |
Added Hien-san, Michael K. from Renesas.
-----Original Message----- From: Geert Uytterhoeven <geert@linux-m68k.org> Sent: Mittwoch, 27. Mai 2020 09:35 To: REE erosca@DE.ADIT-JV.COM <erosca@DE.ADIT-JV.COM> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>; Laurent Pinchart <laurent.pinchart@ideasonboard.com>; Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>; Simon Horman <horms@verge.net.au>; Ulrich Hecht <uli+renesas@fpond.eu>; VenkataRajesh.Kalakodima@in.bosch.com; David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; KOJI MATSUOKA <koji.matsuoka.xm@renesas.com>; muroya@ksk.co.jp; Harsha.ManjulaMallikarjun@in.bosch.com; Ezequiel Garcia <ezequiel@collabora.com>; Sean Paul <seanpaul@chromium.org>; Linux-Renesas <linux-renesas-soc@vger.kernel.org>; DRI Development <dri-devel@lists.freedesktop.org>; Linux Kernel Mailing List <linux-kernel@vger.kernel.org>; Michael Dege <michael.dege@renesas.com>; Gotthard Voellmeke <gotthard.voellmeke@renesas.com>; REE efriedrich@DE.ADIT-JV.COM <efriedrich@DE.ADIT-JV.COM>; Michael Rodin <mrodin@de.adit-jv.com>; ChaitanyaKumar.Borah@in.bosch.com; Eugeniu Rosca <roscaeugeniu@gmail.com> Subject: Re: [PATCH v5 0/8] drm: rcar-du: Add Color Management Module (CMM)
Hi Eugeniu,
On Wed, May 27, 2020 at 9:16 AM Eugeniu Rosca <erosca@de.adit-jv.com> wrote: > On Tue, Oct 15, 2019 at 12:46:13PM +0200, Jacopo Mondi wrote: > > 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 [**]?
While the CMM state will be retained across suspend-to-idle, I'm quite sure it will be lost by suspend-to-RAM, at least on the Salvator-X(S), ULCB, and Ebisu development boards, as PSCI will ask the BD9571WMV regulator to power down the R-Car SoC.
So IMHO we do need suspend/resume handling.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Renesas Electronics Europe GmbH, Geschaeftsfuehrer/President: Carsten Jauch, Sitz der Gesellschaft/Registered office: Duesseldorf, Arcadiastrasse 10, 40472 Duesseldorf, Germany, Handelsregister/Commercial Register: Duesseldorf, HRB 3708 USt-IDNr./Tax identification no.: DE 119353406 WEEE-Reg.-Nr./WEEE reg. no.: DE 14978647
| |