[ATTN] Re: [PATCH v4 5/7] ARM: Exynos: remove code for MFC custom reserved memory handling

From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	Javier Martinez Canillas <javier@osg.samsung.com>,
	linux-media@vger.kernel.org
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
	linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
	Kamil Debski <k.debski@samsung.com>,
	Kukjin Kim <kgene@kernel.org>, Uli Middelberg <uli@middelberg.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: [ATTN] Re: [PATCH v4 5/7] ARM: Exynos: remove code for MFC custom reserved memory handling
Date: Fri, 03 Jun 2016 11:59:41 +0200	[thread overview]
Message-ID: <5751550D.3080404@samsung.com> (raw)
In-Reply-To: <57512A6A.1050209@samsung.com>

On 06/03/2016 08:57 AM, Krzysztof Kozlowski wrote:
> On 06/02/2016 07:25 PM, Javier Martinez Canillas wrote:
>> On 06/02/2016 12:31 PM, Krzysztof Kozlowski wrote:
>>> On 06/02/2016 05:20 PM, Javier Martinez Canillas wrote:
>>>> On 05/30/2016 03:28 AM, Krzysztof Kozlowski wrote:
>>>>> On 05/24/2016 03:31 PM, Marek Szyprowski wrote:
>>>>>> Once MFC driver has been converted to generic reserved memory bindings,
>>>>>> there is no need for custom memory reservation code.
>>>>>>
>>>>>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>>>>>> ---
>>>>>>  arch/arm/mach-exynos/Makefile      |  2 -
>>>>>>  arch/arm/mach-exynos/exynos.c      | 19 --------
>>>>>>  arch/arm/mach-exynos/mfc.h         | 16 -------
>>>>>>  arch/arm/mach-exynos/s5p-dev-mfc.c | 93 -----------------------------
>>>>>>  4 files changed, 130 deletions(-)
>>>>>>  delete mode 100644 arch/arm/mach-exynos/mfc.h
>>>>>>  delete mode 100644 arch/arm/mach-exynos/s5p-dev-mfc.c
>>>>>
>>>>> Thanks, applied.
>>>>
>>>> This patch can't be applied before patches 2/5 and 3/5, or the custom
>>>> memory regions reservation will break with the current s5p-mfc driver.
>>>
>>> Yes, I know. As I understood from talk with Marek, the driver is broken
>>> now so continuous work was not chosen. If it is not correct and full
>>
>> It's true that the driven is currently broken in mainline and is not really
>> stable, I posted fixes for all the issues I found (mostly in module removal
>> and insert paths).
>>
>> But with just the following patch from Ayaka on top of mainline, I'm able to
>> have video decoding working: https://lkml.org/lkml/2016/5/6/577
> 
> Which is still a "future" patch, not current state...
>>
>> Marek mentioned that bisectability is only partially broken because the old
>> binding will still work after this series if IOMMU is enabled (because the
>> properties are ignored in this case). But will break if IOMMU isn't enabled
>> which will be the case for some boards that fails to boot with IOMMU due the
>> bootloader leaving the FIMD enabled doing DMA operations automatically AFAIU. 
>>
>> Now, I'm OK with not keeping backwards compatibility for the MFC dt bindings
>> since arguably the driver has been broken for a long time and nobody cared
>> and also I don't think anyone in practice boots a new kernel with an old DTB
>> for Exynos.
>>
>> But I don't think is correct to introduce a new issue as is the case if this
>> patch is applied before the previous patches in the series since this causes
>> the driver to probe to fail and the following warn on boot (while it used to
>> at least probe correctly in mainline):
> 
> Okay but the patches will go through separate tree. This is not a
> problem, as I said, I just need a stable tag from media tree with first
> four patches (Mauro?).

I have prepared a topic branch including media patches from this patch
series and the dependency fix patches from Javier and Marek.
So this could be used as a topic branch to pull into media master branch
and a dependency topic branch for Krzysztof's samsung-soc tree.
Mauro, can we do it this way? I already talked to Kamil about this.

---8<----
The following changes since commit 1a695a905c18548062509178b98bc91e67510864:

  Linux 4.7-rc1 (2016-05-29 09:29:24 -0700)

are available in the git repository at:

  git://linuxtv.org/snawrocki/samsung.git for-v4.8/media/exynos-mfc

for you to fetch changes up to 04f776734c4e03e33111d3d5a994b589870df623:

  media: s5p-mfc: add iommu support (2016-06-03 11:13:45 +0200)

----------------------------------------------------------------
Javier Martinez Canillas (3):
      s5p-mfc: Set device name for reserved memory region devs
      s5p-mfc: Add release callback for memory region devs
      s5p-mfc: Fix race between s5p_mfc_probe() and s5p_mfc_open()

Marek Szyprowski (6):
      media: vb2-dma-contig: add helper for setting dma max seg size
      media: set proper max seg size for devices on Exynos SoCs
      of: reserved_mem: add support for using more than one region for given device
      media: s5p-mfc: use generic reserved memory bindings
      media: s5p-mfc: replace custom reserved memory handling code with generic one
      media: s5p-mfc: add iommu support

 Documentation/devicetree/bindings/media/s5p-mfc.txt |  39 ++++-
 drivers/media/platform/exynos-gsc/gsc-core.c        |   2 +
 drivers/media/platform/exynos4-is/fimc-core.c       |   2 +
 drivers/media/platform/exynos4-is/fimc-is.c         |   2 +
 drivers/media/platform/exynos4-is/fimc-lite.c       |   2 +
 drivers/media/platform/s5p-g2d/g2d.c                |   2 +
 drivers/media/platform/s5p-jpeg/jpeg-core.c         |   2 +
 drivers/media/platform/s5p-mfc/s5p_mfc.c            | 198 ++++++++++++++-----------
 drivers/media/platform/s5p-mfc/s5p_mfc_iommu.h      |  79 ++++++++++
 drivers/media/platform/s5p-tv/mixer_video.c         |   2 +
 drivers/media/v4l2-core/videobuf2-dma-contig.c      |  53 +++++++
 drivers/of/of_reserved_mem.c                        |  85 ++++++++---
 include/linux/of_reserved_mem.h                     |  25 +++-
 include/media/videobuf2-dma-contig.h                |   2 +
 14 files changed, 379 insertions(+), 116 deletions(-)
 create mode 100644 drivers/media/platform/s5p-mfc/s5p_mfc_iommu.h
---8<----

-- 
Regards,
Sylwester