[PATCH] drm/exynos: resolve infinite loop issue on multi-platform

[Krzysztof Kozlowski]

On czw, 2014-11-06 at 21:32 +0900, Inki Dae wrote:
> On 2014년 11월 06일 21:11, Krzysztof Kozłowski wrote:
> > On 06.11.2014 11:32, Inki Dae wrote:
> >> This patch resolves temporarily infinite loop issue incurred
> >> when Exynos drm driver is enabled and multi-platform kernel
> >> is used by registering Exynos drm device object only in case
> >> of Exynos SoC. So this patch will be replaced with more generic
> >> way later.
> > 
> > Does not help for Rinato board.
> > 
> > On Rinato:
> > -----------------------
> > Failed to find PMU node
> > Registering SWP/SWPB emulation handler
> > mmc0: BKOPS_EN bit is not set
> > mmc_host mmc0: Bus speed (slot 0) = 100000000Hz (slot req 100000000Hz,
> > actual 100000000HZ div = 0)
> > exynos-drm-ipp exynos-drm-ipp: drm ipp registered successfully.
> > mmc0: new HS200 MMC card at address 0001
> > platform exynos-drm: Driver exynos-drm requests probe deferral
> > mmcblk0: mmc0:0001 F5X5MA 3.64 GiB
> > mmcblk0boot0: mmc0:0001 F5X5MA partition 1 4.00 MiB
> > exynos-drm-ipp exynos-drm-ipp: drm ipp registered successfully.
> > mmcblk0boot1: mmc0:0001 F5X5MA partition 2 4.00 MiB
> > platform exynos-drm: Driver exynos-drm requests probe deferral
> > mmcblk0rpmb: mmc0:0001 F5X5MA partition 3 512 KiB
> > exynos-drm-ipp exynos-drm-ipp: drm ipp registered successfully.
> > platform exynos-drm: Driver exynos-drm requests probe deferral
> >  mmcblk0: p1 p2 p3 p4 p5 p6 p7
> > exynos-drm-ipp exynos-drm-ipp: drm ipp registered successfully.
> > platform exynos-drm: Driver exynos-drm requests probe deferral
> > exynos-drm-ipp exynos-drm-ipp: drm ipp registered successfully.
> > platform exynos-drm: Driver exynos-drm requests probe deferral
> > 
> > and so on...
> > -----------------------
> 
> Can you show me compatible string placed on top of exynos3250-rinato.dts
> file? If the compatible has "samsung,exynos3" it should be no problem
> with this patch. And the rinato dts file we posted to mainline has the
> compatible string.

model = "Samsung Rinato board";
compatible = "samsung,rinato-rev05", "samsung,exynos3250",
"samsung,exynos3";

The problem is "samsung,exynos3" because the patch solves only issue on
multiplatform kernel run on non-exynos board. It does not solve the
problem on exynos board with DRM enabled but without all drivers.


> > 
> > I do not know whether it is related but Trats2 board cannot boot due to
> > lockup after:
> > [drm] Initialized drm 1.1.0 20060810
> > (with or without the patch)
> > https://lkml.org/lkml/2014/11/6/125
> > 
> 
> hmm... it's strange because my trats2 board works well with this patch.
> Which kernel did you test? And how can I reproduce above lockup?

Just boot up next-2014110{456} with kernel config attached in mentioned
email.

Best regards,
Krzysztof