From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mauro Carvalho Chehab Date: Mon, 23 Apr 2018 14:25:21 +0000 Subject: Re: [PATCH 5/7] omapfb: omapfb_dss.h: add stubs to build with COMPILE_TEST && DRM_OMAP Message-Id: <20180423112521.52b2a230@vento.lan> List-Id: References: <2542100.cElVns0SR0@amdc3058> <5379683.QunLsIS18Z@amdc3058> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomi Valkeinen Cc: linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , dri-devel@lists.freedesktop.org, Mauro Carvalho Chehab , Laurent Pinchart , Linux Media Mailing List Em Mon, 23 Apr 2018 17:11:14 +0300 Tomi Valkeinen escreveu: > On 23/04/18 16:56, Bartlomiej Zolnierkiewicz wrote: > > > Ideally we should be able to build both drivers in the same kernel > > (especially as modules). > > > > I was hoping that it could be fixed easily but then I discovered > > the root source of the problem: > > > > drivers/gpu/drm/omapdrm/dss/display.o: In function `omapdss_unregister_display': > > display.c:(.text+0x2c): multiple definition of `omapdss_unregister_display' > > drivers/video/fbdev/omap2/omapfb/dss/display.o:display.c:(.text+0x198): first defined here > > The main problem is that omapdrm and omapfb are two different drivers > for the same HW. You need to pick one, even if we would change those > functions and fix the link issue. > > At some point in time we could compile both as modules (but not > built-in), but the only use for that was development/testing and in the > end made our life more difficult. So, now you must fully disable one of > them to enable the other. And, actually, we even have boot-time code, > not included in the module itself, which gets enabled when omapdrm is > enabled. > > While it's of course good to support COMPILE_TEST, if using COMPILE_TEST > with omapfb is problematic, I'm not sure if it's worth to spend time on > that. We should be moving away from omapfb to omapdrm. Yeah, moving away from omapfb sounds the best alternative. As it seems that there's just one driver currently depending on it, I guess it shouldn't be that hard to do such change from Kernel's view, but I may be wrong, as I've no clue what this would mean to userspace. Thanks, Mauro