present: Document the TearFree flip reasons in PresentFlipReason

Adding new flip reasons after the TearFree ones would break the assumption
that `reason >= PRESENT_FLIP_REASON_DRIVER_TEARFREE` implies either of the
TearFree reasons. Document this in the PresentFlipReason enum in order to
save someone a very bad headache in the future.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Reviewed-by: Martin Roukala <martin.roukala@mupuf.org>
This commit is contained in:
Sultan Alsawaf 2023-02-14 19:41:50 -08:00
parent 1fab978a95
commit f490622fca

View File

@ -30,6 +30,12 @@
typedef enum {
PRESENT_FLIP_REASON_UNKNOWN,
PRESENT_FLIP_REASON_BUFFER_FORMAT,
/* Don't add new flip reasons after the TearFree ones, since it's expected
* that the TearFree reasons are the highest ones in order to allow doing
* `reason >= PRESENT_FLIP_REASON_DRIVER_TEARFREE` to check if a reason is
* PRESENT_FLIP_REASON_DRIVER_TEARFREE{_FLIPPING}.
*/
PRESENT_FLIP_REASON_DRIVER_TEARFREE,
PRESENT_FLIP_REASON_DRIVER_TEARFREE_FLIPPING
} PresentFlipReason;