Ville Syrjälä
80cf9a8829
ilk+ planes get notably unhappy when the plane x+w exceeds the stride. This wasn't a problem previously because we always aligned SURF to the closest tile boundary so the x offset never got particularly large. But now with async flips we have to align to 256KiB instead and thus this becomes a real issue. On ilk/snb/ivb it looks like the accesses just wrap early to the next tile row when scanout goes past the SURF+n*stride boundary, hsw/bdw suffer more heavily and start to underrun constantly. i965/g4x appear to be immune. vlv/chv I've not yet checked. Let's borrow another trick from the skl+ code and search backwards for a better SURF offset in the hopes of getting the x offset below the limit. IIRC when I ran into a similar issue on skl years ago it was causing the hardware to fall over pretty hard as well. And let's be consistent and include i965/g4x in the check as well, just in case I just got super lucky somehow when I wasn't able to reproduce the issue. Not that it really matters since we still use 4k SURF alignment for i965/g4x anyway. Fixes:6ede6b0616("drm/i915: Implement async flips for vlv/chv") Fixes:4bb18054ad("drm/i915: Implement async flip for ilk/snb") Fixes:2a636e240c("drm/i915: Implement async flip for ivb/hsw") Fixes:cda195f13a("drm/i915: Implement async flips for bdw") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210209021918.16234-1-ville.syrjala@linux.intel.com Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (cherry picked from commit59fb8218c8) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Rodrigo also exported some functions from intel_display.c during backport]
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.