1f9f9d168c
This fixes an issue where the driver fails with an error:
ioremap error for 0x3f799000-0x3f79a000, requested 0x2, got 0x0
On some platforms the UCSI ACPI mailbox SystemMemory
Operation Region may be setup before the driver has been
loaded. That will lead into the driver failing to map the
mailbox region, as it has been already marked as write-back
memory. acpi_os_ioremap() for x86 uses ioremap_cache()
unconditionally.
When the issue happens, the embedded controller has a
pending query event for the UCSI notification right after
boot-up which causes the operation region to be setup before
UCSI driver has been loaded.
The fix is to notify acpi core that the driver is about to
access memory region which potentially overlaps with an
operation region right before mapping it.
acpi_release_memory() will check if the memory has already
been setup (mapped) by acpi core, and deactivate it (unmap)
if it has. The driver is then able to map the memory with
ioremap_nocache() and set the memtype to uncached for the
region.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.