264b5b5980
In commita78a8da51b("drm/ttm: replace busy placement with flags v6"), the old system of having a separate placement list (for placements which should be used without eviction) and a 'busy' placement list (for placements which should be attempted if eviction is required) was replaced with a new one where placements could be marked 'FALLBACK' (to be attempted if eviction is required) or 'DESIRED' (to be attempted first, but not if eviction is required). i915 had always included the requested placement in the list of 'busy' placements: i.e., the placement could be used either if eviction is required or not. But when the new system was put in place, the requested (first) placement was marked 'DESIRED', so would never be used if eviction became necessary. While a bug in the original commit prevented this flag from working, when this was fixed in4a0e7b3c("drm/i915: fix applying placement flag"), it caused long hangs on DG2 systems with small BAR. Don't mark the requested placement DESIRED (or FALLBACK), allowing it to be used in both situations. This matches the old behaviour, and resolves the hangs. Thanks to Justin Brewer for bisecting the issue. Fixes:a78a8da51b("drm/ttm: replace busy placement with flags v6") Fixes:4a0e7b3c37("drm/i915: fix applying placement flag") Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11255 Signed-off-by: David Gow <david@davidgow.net> Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240804091851.122186-2-david@davidgow.net (cherry picked from commit54bf0af908) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@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 reStructuredText 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.