[PATCH v3 00/19] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem
Javier Martinez Canillas
javier.martinez at collabora.co.uk
Tue Jan 20 06:05:38 PST 2015
Hello Joonyoung,
On 01/20/2015 12:12 PM, Joonyoung Shim wrote:
>>>
>>> I dug further on this issue and found that the cause is that the exynos_mixer
>>> driver needs some clocks (CLK_HDMI and CLK_SCLK_HDMI) grabbed by exynos_hdmi
>>> to be kept enabled after hdmi_poweroff (drivers/gpu/drm/exynos/exynos_hdmi.c).
>>>
>>> Otherwise, any access to mixer device registers leads to an imprecise external
>>> abort error. The following change [0] to the Exynos DRM HDMI driver makes the
>>> issue to not happen and I can successfully execute:
>>>
>>> # echo 1 > /sys/devices/platform/exynos-drm/graphics/fb0/blank
>>> # echo 0 > /sys/devices/platform/exynos-drm/graphics/fb0/blank
>>>
>
> Did you execute this operation repeatedly? Still i get error when i
> execute this more than twice with your change [0].
>
You mean that you are seeing the "Power domain power-domain disable failed"
message but the system is not crashing or that you are still having the
system crash?
I've seen the former when running multiple times but I have not seen the
crash when the hdmi clock is not disabled on hdmi_poweroff().
> Thanks.
>
Best regards,
Javier
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