/**
* drm_modeset_lock_interruptible - take modeset lock
* @lock: lock to take
* @ctx: acquire ctx
*
* Interruptible version of drm_modeset_lock()
*/
int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock,
struct drm_modeset_acquire_ctx *ctx)
{
if (ctx)
return modeset_lock(lock, ctx, true, false);
return ww_mutex_lock_interruptible(&lock->mutex, NULL);
}
/**
* drm_modeset_lock - take modeset lock
* @lock: lock to take
* @ctx: acquire ctx
*
* If ctx is not NULL, then its ww acquire context is used and the
* lock will be tracked by the context and can be released by calling
* drm_modeset_drop_locks(). If -EDEADLK is returned, this means a
* deadlock scenario has been detected and it is an error to attempt
* to take any more locks without first calling drm_modeset_backoff().
*/
int drm_modeset_lock(struct drm_modeset_lock *lock,
struct drm_modeset_acquire_ctx *ctx)
{
if (ctx)
return modeset_lock(lock, ctx, false, false);
ww_mutex_lock(&lock->mutex, NULL);
return 0;
}
/**
* drm_modeset_backoff - deadlock avoidance backoff
* @ctx: the acquire context
*
* If deadlock is detected (ie. drm_modeset_lock() returns -EDEADLK),
* you must call this function to drop all currently held locks and
* block until the contended lock becomes available.
*
* This function returns 0 on success, or -ERESTARTSYS if this context
* is initialized with %DRM_MODESET_ACQUIRE_INTERRUPTIBLE and the
* wait has been interrupted.
*/
int drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx)
{
struct drm_modeset_lock *contended = ctx->contended;
ctx->contended = NULL;
if (WARN_ON(!contended))
return 0;
drm_modeset_drop_locks(ctx);
return modeset_lock(contended, ctx, ctx->interruptible, true);
}
