diff options
| author | Zbigniew Kempczyński <zbigniew.kempczynski@intel.com> | 2023-06-28 08:51:41 +0300 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2023-12-21 19:35:06 +0300 |
| commit | 5572a004685770f8daad7661c5494b65148ede9f (patch) | |
| tree | 6e8bb734e0a9a686c3db3d8baca3c092410af292 /include/uapi/drm | |
| parent | 2e60442a4fef935c76cd70858775b92f565642cc (diff) | |
| download | linux-5572a004685770f8daad7661c5494b65148ede9f.tar.xz | |
drm/xe: Use nanoseconds instead of jiffies in uapi for user fence
Using jiffies as a timeout from userspace is weird even if
theoretically exists possiblity of acquiring jiffies via getconf.
Unfortunately this method is unreliable and the returned
value may vary from the one configured in the kernel config.
Now timeout is expressed in nanoseconds and its interpretation depends
on setting DRM_XE_UFENCE_WAIT_ABSTIME flag. Relative timeout (flag
is not set) means fence expire at now() + timeout. Absolute timeout
(flag is set) means that the fence expires at exact point of time.
Passing negative timeout means we will wait "forever" by setting
wait time to MAX_SCHEDULE_TIMEOUT.
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20230628055141.398036-2-zbigniew.kempczynski@intel.com
Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Diffstat (limited to 'include/uapi/drm')
| -rw-r--r-- | include/uapi/drm/xe_drm.h | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h index 8e7be1551333..347351a8f618 100644 --- a/include/uapi/drm/xe_drm.h +++ b/include/uapi/drm/xe_drm.h @@ -904,8 +904,20 @@ struct drm_xe_wait_user_fence { #define DRM_XE_UFENCE_WAIT_U64 0xffffffffffffffffu /** @mask: comparison mask */ __u64 mask; - - /** @timeout: how long to wait before bailing, value in jiffies */ + /** + * @timeout: how long to wait before bailing, value in nanoseconds. + * Without DRM_XE_UFENCE_WAIT_ABSTIME flag set (relative timeout) + * it contains timeout expressed in nanoseconds to wait (fence will + * expire at now() + timeout). + * When DRM_XE_UFENCE_WAIT_ABSTIME flat is set (absolute timeout) wait + * will end at timeout (uses system MONOTONIC_CLOCK). + * Passing negative timeout leads to neverending wait. + * + * On relative timeout this value is updated with timeout left + * (for restarting the call in case of signal delivery). + * On absolute timeout this value stays intact (restarted call still + * expire at the same point of time). + */ __s64 timeout; /** |