317b2cac79
icl and tgl are still affected by the modulo 4 PLANE_OFFSET.y
underrun issue. Reject such configurations on all gen9+ platforms.
Can be reproduced easily with the following sequence of
hardware poking:
while {
write FBC_CTL.enable=1
wait for vblank
write PLANE_OFFSET .x=0 .y=32
write PLANE_SURF
wait for vblank
# if PLANE_OFFSET.y is multiple of 4 the underrun won't happen
write PLANE_OFFSET .x=0 .y=31
write PLANE_SURF
wait for vblank
# extra vblank wait is required here presumably
# to get FBC into the proper state
wait for vblank
write FBC_CTL.enable=0
# underrun happens some time after FBC disable
wait for vblank
}
Both 8888 and 565 pixel formats and all tilinga formats
seem affected. Reproduced on KBL/GLK/ICL/TGL. BDW confirmed
not affected.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/792
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213133453.22152-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@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.