mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-08 11:50:43 +09:00
d8d2b65a94
Previously portdrv allowed the AER service for any device with an AER capability (assuming Linux had control of AER) even though the AER service driver only attaches to Root Port and RCECs. Because get_port_device_capability() included AER for non-RP, non-RCEC devices, we tried to initialize the AER IRQ even though these devices don't generate AER interrupts. Intel DG1 and DG2 discrete graphics cards contain a switch leading to a GPU. The switch supports AER but not MSI, so initializing an AER IRQ failed, and portdrv failed to claim the switch port at all. The GPU itself could be suspended, but the switch could not be put in a low-power state because it had no driver. Don't allow the AER service on non-Root Port, non-Root Complex Event Collector devices. This means we won't enable Bus Mastering if the device doesn't require MSI, the AER service will not appear in sysfs, and the AER service driver will not bind to the device. Link: https://lore.kernel.org/r/20221207084105.84947-1-mika.westerberg@linux.intel.com Link: https://lore.kernel.org/r/20221210002922.1749403-1-helgaas@kernel.org Based-on-patch-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.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.