Re: [PATCH v2 0/6] Enable HDMI support on Exynos platforms

From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Tobias Jakobi <liquid.acid@gmx.net>,
	Tobias Jakobi <tjakobi@math.uni-bielefeld.de>,
	linux-samsung-soc <linux-samsung-soc@vger.kernel.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>,
	Andrzej Hajda <a.hajda@samsung.com>
Subject: Re: [PATCH v2 0/6] Enable HDMI support on Exynos platforms
Date: Tue, 20 Jan 2015 08:54:10 +0100	[thread overview]
Message-ID: <54BE09A2.2020209@samsung.com> (raw)
In-Reply-To: <54BD8D51.3050202@gmx.net>

Hello,

On 2015-01-20 00:03, Tobias Jakobi wrote:
> Hello!
>
> Marek Szyprowski wrote:
>> Thanks for you tests and pointing this issue. I turned out that the
>> initial fix proposed
>> by Andrzej Hajda
>> (http://www.spinics.net/lists/linux-samsung-soc/msg38915.html) worked
>> fine, while the final version merged to clock fixes ('clk: samsung:
>> exynos4: set parent
>> of sclk_hdmiphy to hdmi' - commit
>> df019a5c0f7083001cb694f44821ca506425bda2) doesn't work
>> properly.
> I should thank you for pushing all this code to mainline. It's really
> nice to see how all the pieces now come together.
>
>
>> Please check the following kernel tree - instead of hacking around hdmi
>> clock I've added
>> handling of it directly to drm mixer driver:
>> https://git.linaro.org/people/marek.szyprowski/linux-srpol.git/shortlog/refs/heads/v3.19-odroid-hdmi
>>
>> I hope that this will finally solve all mixer initialization related
>> issues (also for
>> Odroid XU3, discussed recently in the other thread). If it works fine, I
>> will resend
>> exynos4 hdmi patches to include this change.
> I have picked the additional patches to my tree, which currently has a
> bunch of other stuff in it, in particular v4 of the IOMMU series.

This is a known issue. When Exynos IOMMU DRM driver is enabled, you need 
also
to enabled CONFIG_DRM_EXYNOS_IOMMU, otherwise the driver will crash on init.
This also need to be fixed, but for the time being I focused on other 
issues...

> Anyway, now the 'modetest' application immediately crashes the system,
> but I get a least something on the serial console:
> http://www.math.uni-bielefeld.de/~tjakobi/archive/odroid_modetest_crash_sysmmu.txt
>
> So this is probably due to the IOMMU. Please note that DRM IOMMU support
> (CONFIG_DRM_EXYNOS_IOMMU) was disabled (!) in my config.
> CONFIG_EXYNOS_IOMMU however was on.
>
> I'm going to retest with the IOMMU series removed and
> CONFIG_EXYNOS_IOMMU disabled as well.
>
> Just posting this already since you're probably interested in these
> 'side-issues' as well.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland