This patch implements "verify_crc_source" callback function for
Virtual KMS drm driver.
Changes Since V1:
- update values_cnt in verify_crc_source
Changes Since V2:
- don't return early from set_crc_source to keep behavior same (Haneen)
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180821083858.26275-2-mahesh1.kumar@intel.com
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
