From: Sean Paul seanpaul@chromium.org
This reverts commit 8d813d1a535c8c7503a5f4061654a73026be8c5e.
This patchset breaks on intel platforms and was previously NACK'd by Ville.
Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Fernando Ramos greenfoo@u92.eu Signed-off-by: Sean Paul seanpaul@chromium.org --- drivers/gpu/drm/drm_modeset_lock.c | 94 +++++++++++++++++++++++++++++- include/drm/drm_modeset_lock.h | 2 + 2 files changed, 93 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c index afd1351749a5..fcfe1a03c4a1 100644 --- a/drivers/gpu/drm/drm_modeset_lock.c +++ b/drivers/gpu/drm/drm_modeset_lock.c @@ -77,6 +77,93 @@
static DEFINE_WW_CLASS(crtc_ww_class);
+/** + * drm_modeset_lock_all - take all modeset locks + * @dev: DRM device + * + * This function takes all modeset locks, suitable where a more fine-grained + * scheme isn't (yet) implemented. Locks must be dropped by calling the + * drm_modeset_unlock_all() function. + * + * This function is deprecated. It allocates a lock acquisition context and + * stores it in &drm_device.mode_config. This facilitate conversion of + * existing code because it removes the need to manually deal with the + * acquisition context, but it is also brittle because the context is global + * and care must be taken not to nest calls. New code should use the + * drm_modeset_lock_all_ctx() function and pass in the context explicitly. + */ +void drm_modeset_lock_all(struct drm_device *dev) +{ + struct drm_mode_config *config = &dev->mode_config; + struct drm_modeset_acquire_ctx *ctx; + int ret; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL); + if (WARN_ON(!ctx)) + return; + + mutex_lock(&config->mutex); + + drm_modeset_acquire_init(ctx, 0); + +retry: + ret = drm_modeset_lock_all_ctx(dev, ctx); + if (ret < 0) { + if (ret == -EDEADLK) { + drm_modeset_backoff(ctx); + goto retry; + } + + drm_modeset_acquire_fini(ctx); + kfree(ctx); + return; + } + ww_acquire_done(&ctx->ww_ctx); + + WARN_ON(config->acquire_ctx); + + /* + * We hold the locks now, so it is safe to stash the acquisition + * context for drm_modeset_unlock_all(). + */ + config->acquire_ctx = ctx; + + drm_warn_on_modeset_not_all_locked(dev); +} +EXPORT_SYMBOL(drm_modeset_lock_all); + +/** + * drm_modeset_unlock_all - drop all modeset locks + * @dev: DRM device + * + * This function drops all modeset locks taken by a previous call to the + * drm_modeset_lock_all() function. + * + * This function is deprecated. It uses the lock acquisition context stored + * in &drm_device.mode_config. This facilitates conversion of existing + * code because it removes the need to manually deal with the acquisition + * context, but it is also brittle because the context is global and care must + * be taken not to nest calls. New code should pass the acquisition context + * directly to the drm_modeset_drop_locks() function. + */ +void drm_modeset_unlock_all(struct drm_device *dev) +{ + struct drm_mode_config *config = &dev->mode_config; + struct drm_modeset_acquire_ctx *ctx = config->acquire_ctx; + + if (WARN_ON(!ctx)) + return; + + config->acquire_ctx = NULL; + drm_modeset_drop_locks(ctx); + drm_modeset_acquire_fini(ctx); + + kfree(ctx); + + mutex_unlock(&dev->mode_config.mutex); +} +EXPORT_SYMBOL(drm_modeset_unlock_all); + /** * drm_warn_on_modeset_not_all_locked - check that all modeset locks are locked * @dev: device @@ -293,9 +380,10 @@ EXPORT_SYMBOL(drm_modeset_unlock); * This function takes all modeset locks, suitable where a more fine-grained * scheme isn't (yet) implemented. * - * It doesn't take the &drm_mode_config.mutex since that lock isn't required for - * modeset state changes. Callers which need to grab that lock too need to do so - * outside of the acquire context @ctx. + * Unlike drm_modeset_lock_all(), it doesn't take the &drm_mode_config.mutex + * since that lock isn't required for modeset state changes. Callers which + * need to grab that lock too need to do so outside of the acquire context + * @ctx. * * Locks acquired with this function should be released by calling the * drm_modeset_drop_locks() function on @ctx. diff --git a/include/drm/drm_modeset_lock.h b/include/drm/drm_modeset_lock.h index 865e64bcc4cb..aafd07388eb7 100644 --- a/include/drm/drm_modeset_lock.h +++ b/include/drm/drm_modeset_lock.h @@ -132,6 +132,8 @@ struct drm_device; struct drm_crtc; struct drm_plane;
+void drm_modeset_lock_all(struct drm_device *dev); +void drm_modeset_unlock_all(struct drm_device *dev); void drm_warn_on_modeset_not_all_locked(struct drm_device *dev);
int drm_modeset_lock_all_ctx(struct drm_device *dev,