d46b60a2e8
Currently we leave the cache_level of the initial fb obj set to NONE. This means on eLLC machines the first pin_to_display() will try to switch it to WT which requires a vma unbind+bind. If that happens during the fbdev initialization rcu does not seem operational which causes the unbind to get stuck. To most appearances this looks like a dead machine on boot. Avoid the unbind by already marking the object cache_level as WT when creating it. We still do an excplicit ggtt pin which will rewrite the PTEs anyway, so they will match whatever cache level we set. Cc: <stable@vger.kernel.org> # v5.7+ Suggested-by: Chris Wilson <chris@chris-wilson.co.uk> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2381 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20201007120329.17076-1-ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20201015122138.30161-1-chris@chris-wilson.co.uk
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.