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On the MediaTek platform, some SMI LARBs are directly connected to
the SMI Common, while others are connected to the SMI Sub-Common,
which in turn is connected to the SMI Common. The hardware block
diagram can be described as follows.
SMI-Common(Smart Multimedia Interface Common)
|
+----------------+------------------+
| | |
| | |
| | |
| | |
| | |
larb0 SMI-Sub-Common0 SMI-Sub-Common1
| | | | |
larb1 larb2 larb3 larb7 larb9
For previous discussion on the direction of the code modifications,
please refer to:
https://lore.kernel.org/all/CAFGrd9qZhObQXvm2_abqaX83xMLqxjQETB2=
wXpobDWU1CnvkA@mail.gmail.com/
https://lore.kernel.org/all/CAPDyKFpokXV2gJDgowbixTvOH_5VL3B5H8ey
hP+KJ5Fasm2rFg@mail.gmail.com/
On the MediaTek MT8188 SoC platform, we encountered power-off failures
and SMI bus hang issues during camera stress tests. The issue arises
because bus glitches are sometimes produced when MTCMOS powers on or
off. While this is fairly normal, the software must handle these
glitches to avoid mistaking them for transaction signals. What's
more, this issue emerged only after the initial upstreaming of this
binding. Without these patches, the SMI becomes unstable during camera
stress tests.
The software solutions can be summarized as follows:
1. Use CLAMP to disable the SMI sub-common port after turning off the
LARB CG and before turning off the LARB MTCMOS.
2. Use CLAMP to disable/enable the SMI sub-common port.
3. Implement an AXI reset for SMI LARBs.
This patch add '#reset-cells' for the clock controller located in image,
camera and IPE subsystems.
Signed-off-by: Friday Yang <friday.yang@mediatek.com>
Link: https://lore.kernel.org/r/20250221075058.14180-2-friday.yang@mediatek.com
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.