b1012ca8dc
The VT-d spec requires (10.4.4 Global Command Register, TE field) that: Hardware implementations supporting DMA draining must drain any in-flight DMA read/write requests queued within the Root-Complex before completing the translation enable command and reflecting the status of the command through the TES field in the Global Status register. Unfortunately, some integrated graphic devices fail to do so after some kind of power state transition. As the result, the system might stuck in iommu_disable_translation(), waiting for the completion of TE transition. This provides a quirk list for those devices and skips TE disabling if the qurik hits. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=208363 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=206571 Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Tested-by: Koba Ko <koba.ko@canonical.com> Tested-by: Jun Miao <jun.miao@windriver.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200723013437.2268-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
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.