5ef8100a39
Currently, we flush pending CRC workers very late in the commit flow, when we destroy all the old crtc states. Unfortunately, at that point, the framebuffers are already unpinned (and our vaddr possible gone), so this isn't good. Also, the plane_states we need might also already be cleaned up, since cleanup order of state structures isn't well defined. Fix this by waiting for all CRC workers of the old state to complete before we start any of the cleanup work. For correct ordering and avoiding races, we can only flush_work after drm_atomic_helper_wait_for_vblanks() since we know that all subsequent queue_work will be for the new state. Only once that's done is flush_work() useful, before that we might flush the work, and then right after the hrtimer that simulates vblank queues it again. Every time you have a flush_work before cleaning up the work structure, the following sequence must be obeyed, or it can go wrong: 1. Make sure no one else can re-queue the work anymore (in our case that's done by a combination of first updating output->crc_state and then waiting for the vblank to pass to make sure the hrtimer has noticed that change). 2. flush_work() 3. Actually clean up stuff (which isn't done here). Doing the flush_work before we even completed the output->state update, much less waited for the vblank to make sure that's happened, missed the point. Note that this is not yet race-free because of the hrtimer and crc worker look at the wrong state pointers, but that will be fixed in subsequent patches. Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Cc: Haneen Mohammed <hamohammed.sa@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Tested-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190606222751.32567-7-daniel.vetter@ffwll.ch |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.