Hiago De Franco 6b8a8eac58 remoteproc: imx_rproc: skip clock enable when M-core is managed by the SCU
[ Upstream commit 496deecb020d14ba89ba7084fbc3024f91687023 ]

For the i.MX8X and i.MX8 family SoCs, when the Cortex-M core is powered
up and started by the Cortex-A core using the bootloader (e.g., via the
U-Boot bootaux command), both M-core and Linux run within the same SCFW
(System Controller Firmware) partition. With that, Linux has permission
to control the M-core.

But once the M-core is started by the bootloader, the SCFW automatically
enables its clock and sets the clock rate. If Linux later attempts to
enable the same clock via clk_prepare_enable(), the SCFW returns a
'LOCKED' error, as the clock is already configured by the SCFW. This
causes the probe function in imx_rproc.c to fail, leading to the M-core
power domain being shut down while the core is still running. This
results in a fault from the SCU (System Controller Unit) and triggers a
system reset.

To address this issue, ignore handling the clk for i.MX8X and i.MX8
M-core, as SCFW already takes care of enabling and configuring the
clock.

Suggested-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20250629172512.14857-3-hiagofranco@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28 16:28:16 +02:00
2022-09-28 09:02:20 +02:00
2025-08-15 12:09:09 +02:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%