Hi Mauro, On Monday, 23 April 2018 17:22:27 EEST Mauro Carvalho Chehab wrote: > Em Mon, 23 Apr 2018 15:56:53 +0200 Bartlomiej Zolnierkiewicz escreveu: > > On Monday, April 23, 2018 02:47:28 PM Bartlomiej Zolnierkiewicz wrote: > >> On Friday, April 20, 2018 01:42:51 PM Mauro Carvalho Chehab wrote: > >>> Add stubs for omapfb_dss.h, in the case it is included by > >>> some driver when CONFIG_FB_OMAP2 is not defined, with can > >>> happen on ARM when DRM_OMAP is not 'n'. > >>> > >>> That allows building such driver(s) with COMPILE_TEST. > >>> > >>> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> > >> > >> This patch should be dropped (together with patch #6/7) as it was > >> superseded by a better solution suggested by Laurent: > >> > >> https://patchwork.kernel.org/patch/10325193/ > >> > >> ACK-ed by Tomi: > >> > >> https://www.spinics.net/lists/dri-devel/msg171918.html > >> > >> and already merged by you (commit 7378f1149884 "media: omap2: > >> omapfb: allow building it with COMPILE_TEST").. > > > > Hmm, I see now while this patch is still included: > > > > menuconfig FB_OMAP2 > > tristate "OMAP2+ frame buffer support" > > depends on FB > > depends on DRM_OMAP = n > > > > 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 ... > > Yes, and declared on two different places: > > drivers/gpu/drm/omapdrm/dss/omapdss.h:void omapdss_unregister_display(struct > omap_dss_device *dssdev); include/video/omapfb_dss.h:void > omapdss_unregister_display(struct omap_dss_device *dssdev); > > one alternative would be to give different names to it, and a common > header for both. > > At such header, it could be doing something like: > > static inline void omapdss_unregister_display(struct omap_dss_device > *dssdev) { > #if enabled(CONFIG_DRM_OMAP) > omapdss_unregister_display_drm(struct omap_dss_device *dssdev); > #else > omapdss_unregister_display_fb(struct omap_dss_device *dssdev); > ##endif > } > > Yet, after a very quick check, it seems that nowadays only the > media omap driver uses the symbols at FB_OMAP: > > $ git grep omapfb_dss.h > drivers/media/platform/omap/omap_vout.c:#include <video/omapfb_dss.h> > drivers/media/platform/omap/omap_voutdef.h:#include <video/omapfb_dss.h> > drivers/media/platform/omap/omap_voutlib.c:#include <video/omapfb_dss.h> > > So, perhaps just renaming the common symbols and changing FB_OMAP2 to: > > menuconfig FB_OMAP2 > tristate "OMAP2+ frame buffer support" > depends on FB > depends on (DRM_OMAP = n) || COMPILE_TEST > > would be enough to allow to build both on ARM. I don't think it's worth it renaming the common symbols. They will change over time as omapdrm is under heavy rework, and it's painful enough without having to handle cross-tree changes. Let's just live with the fact that both drivers can't be compiled at the same time, given that omapfb is deprecated. > > I need some more time to think about this.. -- Regards, Laurent Pinchart
