14858dcc3b
Updating the current_state field of struct pci_dev the way it is done
in pci_enable_device_flags() before calling do_pci_enable_device() may
not work. For example, if the given PCI device depends on an ACPI
power resource whose _STA method initially returns 0 ("off"), but the
config space of the PCI device is accessible and the power state
retrieved from the PCI_PM_CTRL register is D0, the current_state
field in the struct pci_dev representing that device will get out of
sync with the power.state of its ACPI companion object and that will
lead to power management issues going forward.
To avoid such issues, make pci_enable_device_flags() call
pci_update_current_state() which takes ACPI device power management
into account, if present, to retrieve the current power state of the
device.
Link: https://lore.kernel.org/lkml/20210314000439.3138941-1-luzmaximilian@gmail.com/
Reported-by: Maximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Maximilian Luz <luzmaximilian@gmail.com>
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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 | ||
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.
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.