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
This patch implement the necessary functions to compute and add CRCs
entries:
- Implement the set_crc_source() callback.
- Compute CRC using crc32 on the visible part of the framebuffer.
- Use ordered workqueue per output to compute and add CRC at the end
of a vblank.
- Use appropriate synchronization methods since the CRC computation must
be atomic wrt the generated vblank event for a given atomic update, by
using spinlock across atomic_begin/atomic_flush to wrap the event
handling code completely and match the flip event with the CRC.
Since vkms_crc_work_handle() can sleep, spinlock can't be acquired
while accessing vkms_output->primary_crc to compute CRC.
To make sure the data is updated and released without conflict with
the vkms_crc_work_handle(), the work_struct is flushed @crtc_destroy
and the data is updated before scheduling the work handle again, as
follow:
* CRC data update:
1- store vkms_crc_data {fb, src} per plane_state
2- @plane_duplicate_state -> allocate vkms_crc_data
3- during atomic commit (@atomic_update) ->
a) copy {fb, src} to plane_state->crc_data
b) get reference to fb,
3- @plane_destroy_state -> a) if (fb refcount) remove reference to fb
b) deallocate crc_data
* Atomic Commit:
1- vkms_plane_atomic_check
2- vkms_prepare_fb -> vmap vkms_gem_obj->vaddr
3- atomic_begin -> hold crc spinlock
4- atomic_plane_update -> a) update vkms_output->primary_crc
b) get reference to fb
5- atomic_flush -> a) send vblank event while holding event_lock
b) release crc spinlock
* hrtimer regular callback:
1- hold crc spinlock
2- drm_crtc_handle_vblank()
3- queue vkms_crc_work_handle
4- release crc spinlock
* cleanup:
1- @cleanup_fb ->vunmap vkms_gem_obj->vaddr
2- @crtc_destroy -> flush work struct
3- @plane_destroy -> a) if (fb refcount) remove reference to fb
b) deallocate crc_data
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[seanpaul fixed typo in vkms_crtc s/vblamk/vblank/]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b948327f48c3e70ab232b4a0848ee6d033b26484.1533171495.git.hamohammed.sa@gmail.com
Currently, vkms shows an error message if the following steps occur: (1)
load vkms, (2) perform any specific operation in the vkms (e.g., run an
IGT test), and (3) unload the module. The following error message
emerges:
[drm:drm_mode_config_cleanup [drm]] *ERROR* connector Virtual-1 leaked!
This commit fixes this error by calling drm_atomic_helper_shutdown()
before drm_mode_config_cleanup, which turns off the whole display
pipeline and remove a reference related to any connector.
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180719004045.hzepp565x5lfco3c@smtp.gmail.com
This commit adds regular vblank events simulated through hrtimers, which
is a feature required by VKMS to mimic real hardware. Additionally, all
the vblank event send after pageflip is kept in the atomic_flush
function.
Changes since V1:
- Compute the vblank timer interval per interruption
Ville Syrjälä and Daniel Vetter:
- Removes hardcoded vblank interval to get it from user space
Changes since V2:
Chris Wilson
- Removes unnecessary algorithm to compute the next period
Daniel Vetter:
- Uses drm_calc_timestamping_constants to get the vblank interval
instead of calculating it manually
- Adds disable_vblank helper that turns of crtc
- Simplifies implementation by using drm_crtc_arm_vblank_event
- Replaces the code in atomic_begin to atomic_flush
- Removes unnecessary field in vkms_output
Changes since V3:
Daniel Vetter:
- Squash "drm/vkms: Add atomic helpers functions" into the commit that
handling vblank events simulated by hrtimers
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/7709bba40782ec06332d57fff337797b272581fc.1531359228.git.rodrigosiqueiramelo@gmail.com
