5ff7bec678
[ Upstream commit eaa225b6b52233d45457fd33730e1528c604d92d ] Komeda driver relies on the generic DRM atomic helper functions to handle commits. It only implements an atomic_commit_tail hook for the mode_config_helper_funcs and even that one is pretty close to the generic implementation with the exception of additional dma_fence signalling. What the generic helper framework doesn't do is waiting for the actual hardware to signal that the commit parameters have been written into the appropriate registers. As we signal CRTC events only on the irq handlers, we need to flush the configuration and wait for the hardware to respond. Add the Komeda specific implementation for atomic_commit_hw_done() that flushes and waits for flip done before calling drm_atomic_helper_commit_hw_done(). The fix was prompted by a patch from Carsten Haitzler where he was trying to solve the same issue but in a different way that I think can lead to wrong event signaling to userspace. Reported-by: Carsten Haitzler <carsten.haitzler@arm.com> Tested-by: Carsten Haitzler <carsten.haitzler@arm.com> Reviewed-by: Carsten Haitzler <carsten.haitzler@arm.com> Signed-off-by: Liviu Dudau <liviu.dudau@arm.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220722122139.288486-1-liviu.dudau@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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.