mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-06 10:58:48 +09:00
ac4d189aaa
[ Upstream commit c0485e864a2eaa1d5a84c71e573dd236d0e885ae ]
EUD_MODE_MANAGER2 register is mapped to a memory region that is marked
as read-only for operating system running at EL1, enforcing access
restrictions that prohibit direct memory-mapped writes via writel().
Attempts to write to this region from HLOS can result in silent failures
or memory access violations, particularly when toggling EUD (Embedded
USB Debugger) state. To ensure secure register access, modify the driver
to use qcom_scm_io_writel(), which routes the write operation to Qualcomm
Secure Channel Monitor (SCM). SCM has the necessary permissions to access
protected memory regions, enabling reliable control over EUD state.
SC7280, the only user of EUD is also affected, indicating that this could
never have worked on a properly fused device.
Fixes: 9a1bf58ccd ("usb: misc: eud: Add driver support for Embedded USB Debugger(EUD)")
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Signed-off-by: Komal Bajaj <komal.bajaj@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250731-eud_mode_manager_secure_access-v8-1-4a5dcbb79f41@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@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 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.