From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [RFC v2 6/8] gpu: drm: tegra: Remove redundant host1x Date: Fri, 04 Jan 2013 13:25:06 -0700 Message-ID: <50E73AA2.7090500@wwwdotorg.org> References: <50BF345A.8050201@nvidia.com> <20121205120429.GA29943@avionic-0098.adnet.avionic-design.de> <50C5CAB5.3040000@nvidia.com> <20121212160829.GA30278@avionic-0098.adnet.avionic-design.de> <50C99677.6090306@nvidia.com> <20121213085750.GA14740@avionic-0098.adnet.avionic-design.de> <50CA175F.60002@wwwdotorg.org> <50CAC2AC.1010704@nvidia.com> <50CB5205.1030303@wwwdotorg.org> <50CB850F.9090704@nvidia.com> <20121216121603.GA31780@avionic-0098.adnet.avionic-design.de> <50D2D792.1050401@nvidia.com> <50D34775.5010606@wwwdotorg.org> <50D42486.7080901@nvidia.com> <50D4D25B.7030506@wwwdotorg.org> <50E6AA69.4030001@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <50E6AA69.4030001-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?UTF-8?B?VGVyamUgQmVyZ3N0csO2bQ==?= Cc: Arto Merilainen , Thierry Reding , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 01/04/2013 03:09 AM, Terje Bergstr=C3=B6m wrote: =2E.. > I think we have now two ways to go forward with cons and pros: > 1) Keep host1x and tegra-drm as separate driver > + Code almost done > - we need dummy device and dummy driver > - extra code and API when host1x creates dummy device and its pass= ed > to tegra-drm Just to play devil's advocate: I suspect that's only a few lines of code. > - tegra-drm device would need to be a child of host1x device. Havi= ng > virtual and real devices as host1x children sounds weird. And I doubt that would cause problems. > 2) Merge host1x and tegra-drm into one module. drm is a subcomponent= , > and whatever other personalities we wish would also be subcomponents = of > host1x. host1x calls tegra-drm directly to handle preparation for drm > initialization. As they're in the same module, circular dependency is= ok. > + Simpler conceptually (no dummy device/driver) > + Less code > - Proposal doesn't yet exist But that said, I agree this approach would be very reasonable; it seems to me that host1x really is the main HW behind a DRM driver or a V4L2 driver or ... As such, it seems quite reasonable for a single struct device to exist that represents host1x, and for the driver for that device to register both a DRM and a V4L2 driver etc. The code could physically be organized into separate modules, and under different Kconfig options for configurability etc. But either way, I'll let you (Thierry and Terje) work out which way to = go.