7484a5bc15
During the driver conversion to shmem, the start address for the
scanout buffer was set to the base PCI address.
In most cases it works because only the lower 24bits are used, and
due to alignment it was almost always 0.
But on some unlucky hardware, it's not the case, and some uninitialized
memory is displayed on the BMC.
With shmem, the primary plane is always at offset 0 in GPU memory.
* v2: rewrite the patch to set the offset to 0. (Thomas Zimmermann)
* v3: move the change to plane_init() and also fix the cursor plane.
(Jammy Huang)
Tested on a sr645 affected by this bug.
Fixes: f2fa5a99ca81 ("drm/ast: Convert ast to SHMEM")
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jammy Huang <jammy_huang@aspeedtech.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230209094417.21630-1-jfalempe@redhat.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.