On 11/06/2014 07:23 AM, Inki Dae wrote: > On 2014ë 11ì 05ì¼ 23:38, Thierry Reding wrote: >> On Tue, Nov 04, 2014 at 09:18:46PM +0400, Matwey V. Kornilov wrote: >>> Hi, >>> >>> I run 3.18-rc3 kernel on BeagleBone Black. It doesn't have Exynos DRM >>> of course, but I run multi-platform kernel where CONFIG_DRM_EXYNOS is >>> set to 'y'. >>> The issue here is that the platform probe/init goes to infinite loop >>> as the following: >>> >>> [ 5.717343] platform exynos-drm: Driver exynos-drm requests probe >>> deferral >>> [ 5.726848] exynos-drm-ipp exynos-drm-ipp: drm ipp registered >>> successfully. >>> [ 5.734700] platform exynos-drm: Driver exynos-drm requests probe >>> deferral >>> [ 5.744044] exynos-drm-ipp exynos-drm-ipp: drm ipp registered >>> successfully. >>> [ 5.752010] platform exynos-drm: Driver exynos-drm requests probe >>> deferral >>> [ 5.761377] exynos-drm-ipp exynos-drm-ipp: drm ipp registered >>> successfully. >>> [ 5.769291] platform exynos-drm: Driver exynos-drm requests probe >>> deferral >>> >>> It is quite unexpectable behavior. I would expect that the exynos-drm >>> failed to initialize with 'no device' error. >>> >>> See also for the reference: >>> https://bugzilla.kernel.org/show_bug.cgi?id=87691 >> >> The reason for this seems to be that Exynos DRM instantiates a dummy >> device that it can bind to (see exynos_drm_init()). Now this code is >> executed unconditonally, so the device will be created whether or not >> the kernel/module runs on an Exynos SoC. The driver should really bind >> to some real device rather than instantiating a dummy. Or if it must >> bind to a dummy then the code needs to at least check that it's running >> on an Exynos SoC before instantiating the dummy. >> > > Right, I also think the problem is because we use a dummay device for > Exynos drm. As you mentioned, this device can always be bound as long as > Exynos drm driver is enabled even without real device. So this issue > gives us that we need super device node again. Actually, I had already > tried the use of the super device node like below for Exynos drm but > other Samsung guys didn't want to use it. > http://lists.freedesktop.org/archives/dri-devel/2014-April/056618.html > > I think now we have the reason that we should use super device node so I > will try to support the super device for Exynos drm like other ARM drm > drivers did. However, for this, I'd like to listen to other opinions > for a while before that.
It is enough to check if there are platform devices compatible with drivers registered by exynos_drm_dev. Regards Andrzej > > Thanks, > Inki Dae > >> Thierry >> >> >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel at lists.freedesktop.org >> http://lists.freedesktop.org/mailman/listinfo/dri-devel >> > > _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel >
