f20e232d74
The definition of L1TCM_SRAM_PDN bits on mt8195 is different to mt8192.
L1TCM_SRAM_PDN bits[3:0] control the power of mt8195 L1TCM SRAM.
L1TCM_SRAM_PDN bits[7:4] control the access path to EMI for SCP.
These bits have to be powered on to allow EMI access for SCP.
Bits[7:4] also affect audio DSP because audio DSP and SCP are
placed on the same hardware bus. If SCP cannot access EMI, audio DSP is
blocked too.
L1TCM_SRAM_PDN bits[31:8] are not used.
This fix removes modification of bits[7:4] when power on/off mt8195 SCP
L1TCM. It's because the modification introduces a short period of time
blocking audio DSP to access EMI. This was not a problem until we have
to load both SCP module and audio DSP module. audio DSP needs to access
EMI because it has source/data on DRAM. Audio DSP will have unexpected
behavior when it accesses EMI and the SCP driver blocks the EMI path at
the same time.
Fixes: 79111df414fc ("remoteproc: mediatek: Support mt8195 scp")
Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20220321060340.10975-1-tinghan.shen@mediatek.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.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 Restructured Text 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.