04b12ef163
When Samsung PCIe Gen4 NVMe is connected to Intel ADL VMD, the combination causes AER message flood and drags the system performance down. The issue doesn't happen when VMD mode is disabled in BIOS, since AER isn't enabled by acpi_pci_root_create() . When VMD mode is enabled, AER is enabled regardless of _OSC: [ 0.410076] acpi PNP0A08:00: _OSC: platform does not support [AER] ... [ 1.486704] pcieport 10000:e0:06.0: AER: enabled with IRQ 146 Since VMD is an aperture to regular PCIe root ports, honor ACPI _OSC to disable PCIe features accordingly to resolve the issue. Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215027 Link: https://lore.kernel.org/r/20211203031541.1428904-1-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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.