On 2014년 11월 07일 22:53, Krzysztof Kozlowski wrote: > During system resume from suspend to RAM the Exynos DRM driver forced > CRTC mode thus turning display on (DPMS_ON). This lead to runtime resuming > of DSI which failed because whole LCD power domain was off and it was > not allowed to turn on because of system resume in progress. > > Forcing mode should not be needed and removing it solves this particular > problem.
only this patch, Applied. Thanks, Inki Dae > > This necessary fix for following scenario reproduced on Exynos DRM: > 1. Power domain is off before suspending the system. > 2. System is suspended to RAM. > 3. Resuming starts. The Exynos DRM driver resume callback is called. > 4. The Exynos DRM driver calls drm_helper_resume_force_mode() which turns > on the screen by calling exynos_dsi_dpms with DRM_MODE_DPMS_ON. > 5. The Exynos DSI driver calls pm_runtime_get. The driver runtime > resumes and this should turn LCD power domain on. > 6. Unfortunately the domain cannot be turned on because system resume is > in progress and genpd->prepared_count is positive. > > Steps to reproduce: > 1. Add runtime PM to Exynos DSI driver. > 2. Build Exynos DRM/FB without FRAMEBUFFER_CONSOLE. > 3. Enable the connector and screen (e.g. with modeset-vsync). > 4. echo 3 > /sys/devices/platform/exynos-drm/graphics/fb0/blank > 5. echo mem > /sys/power/state > 6. Resume. > [ 77.712469] PM: early resume of devices complete after 3.854 msecs > [ 77.712739] exynos-dsi 11c80000.dsi: pm_genpd_resume() > [ 77.712758] exynos4-fimc 11800000.fimc: pm_genpd_resume() > [ 77.712774] exynos4-fimc 11810000.fimc: pm_genpd_resume() > [ 77.712787] exynos-drm-fimc 11820000.fimc: pm_genpd_resume() > [ 77.712802] exynos-drm-fimc 11830000.fimc: pm_genpd_resume() > [ 77.712815] s5p-mipi-csis 11880000.csis: pm_genpd_resume() > [ 77.712829] s5p-mipi-csis 11890000.csis: pm_genpd_resume() > [ 77.712843] exynos-fimc-lite 12390000.fimc-lite: pm_genpd_resume() > [ 77.712856] exynos-fimc-lite 123a0000.fimc-lite: pm_genpd_resume() > [ 77.713788] exynos4-fb 11c00000.fimd: pm_genpd_resume() > [ 77.713912] wake disabled for irq 184 > [ 77.713923] wake disabled for irq 185 > [ 77.714082] wake disabled for irq 173 > [ 77.715676] wake disabled for irq 176 > [ 77.718540] exynos4-fb 11c00000.fimd: pm_genpd_runtime_resume() > [ 77.718567] exynos4-fb 11c00000.fimd: state restore latency exceeded, new > value 1708 ns > [ 77.718636] exynos-dsi 11c80000.dsi: pm_genpd_runtime_resume() > [ 77.892366] exynos-dsi 11c80000.dsi: PLL failed to stabilize > [ 77.892377] exynos-dsi 11c80000.dsi: failed to configure DSI PLL > [ 78.192168] exynos-dsi 11c80000.dsi: timeout waiting for reset > [ 78.211578] exynos-dsi 11c80000.dsi: waiting for bus lanes timed out > [ 78.307173] exynos-dsi 11c80000.dsi: xfer timed out: d1 00 (null) > [ 78.307190] panel_s6e8aa0 11c80000.dsi.0: error -110 reading dcs seq(0xd1) > [ 78.307199] panel_s6e8aa0 11c80000.dsi.0: read id failed > > Signed-off-by: Krzysztof Kozlowski <k.kozlow...@samsung.com> > --- > drivers/gpu/drm/exynos/exynos_drm_drv.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c > b/drivers/gpu/drm/exynos/exynos_drm_drv.c > index d32165a7f862..8f7110c9d21f 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c > @@ -200,8 +200,6 @@ static int exynos_drm_resume(struct drm_device *dev) > } > drm_modeset_unlock_all(dev); > > - drm_helper_resume_force_mode(dev); > - > return 0; > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
