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authorDave Airlie <airlied@redhat.com>2017-09-28 05:45:27 +1000
committerDave Airlie <airlied@redhat.com>2017-09-28 05:46:15 +1000
commit29baa82aa55f40d67cfc8138c944fd8880c27e8e (patch)
tree19119a07d3ec8eb1407a68b48ec627239ee3e681 /drivers/gpu/drm/drm_modeset_lock.c
parente19b205be43d11bff638cad4487008c48d21c103 (diff)
parentac6c35a4d8c77083525044a192cb1a8711381e94 (diff)
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Merge tag 'drm-misc-next-2017-09-20' of git://anongit.freedesktop.org/git/drm-misc into drm-next
UAPI Changes: Cross-subsystem Changes: Core Changes: - DP SDP defines (Ville) - polish for scdc helpers (Thierry Reding) - fix lifetimes for connector/plane state across crtc changes (Maarten Lankhorst). - sparse fixes (Ville+Thierry) - make legacy kms ioctls all interruptible (Maarten) - push edid override into the edid helpers (out of probe helpers) (Jani) - DP ESI defines for link status (DK) Driver Changes: - drm-panel is now in drm-misc! - minor panel-simple cleanups/refactoring by various folks - drm_bridge_add cleanup (Inki Dae) - constify a few i2c_device_id structs (Arvind Yadav) - More patches from Noralf's fb/gem helper cleanup - bridge/synopsis: reset fix (Philippe Cornu) - fix tracepoint include handling in drivers (Thierry) - rockchip: lvds support (Sandy Huang) - move sun4i into drm-misc fold (Maxime Ripard) - sun4i: refactor driver load + support TCON backend/layer muxing (Chen-Yu Tsai) - pl111: support more pl11x variants (Linus Walleij) - bridge/adv7511: robustify probing/edid handling (Lars-Petersen Clausen) New hw support: - S6E63J0X03 panel (Hoegeun Kwon) - OTM8009A panel (Philippe CORNU) - Seiko 43WVF1G panel (Marco Franchi) - tve200 driver (Linus Walleij) Plus assorted of tiny patches all over, including our first outreachy patches from applicants for the winter round! * tag 'drm-misc-next-2017-09-20' of git://anongit.freedesktop.org/git/drm-misc: (101 commits) drm: add backwards compatibility support for drm_kms_helper.edid_firmware drm: handle override and firmware EDID at drm_do_get_edid() level drm/dp: DPCD register defines for link status within ESI field drm/rockchip: Replace dev_* with DRM_DEV_* drm/tinydrm: Drop driver registered message drm/gem-fb-helper: Use debug message on gem lookup failure drm/imx: Use drm_gem_fb_create() and drm_gem_fb_prepare_fb() drm/bridge: adv7511: Constify HDMI CODEC platform data drm/bridge: adv7511: Enable connector polling when no interrupt is specified drm/bridge: adv7511: Remove private copy of the EDID drm/bridge: adv7511: Properly update EDID when no EDID was found drm/crtc: Convert setcrtc ioctl locking to interruptible. drm/atomic: Convert pageflip ioctl locking to interruptible. drm/legacy: Convert setplane ioctl locking to interruptible. drm/legacy: Convert cursor ioctl locking to interruptible. drm/atomic: Convert atomic ioctl locking to interruptible. drm/atomic: Prepare drm_modeset_lock infrastructure for interruptible waiting, v2. drm/tve200: Clean up panel bridging drm/doc: Update todo.rst drm/dp/mst: Sideband message transaction to power up/down nodes ...
Diffstat (limited to 'drivers/gpu/drm/drm_modeset_lock.c')
-rw-r--r--drivers/gpu/drm/drm_modeset_lock.c96
1 files changed, 48 insertions, 48 deletions
diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
index af4e906c630d..e123497da0ca 100644
--- a/drivers/gpu/drm/drm_modeset_lock.c
+++ b/drivers/gpu/drm/drm_modeset_lock.c
@@ -39,23 +39,28 @@
*
* The basic usage pattern is to::
*
- * drm_modeset_acquire_init(&ctx)
+ * drm_modeset_acquire_init(ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE)
* retry:
* foreach (lock in random_ordered_set_of_locks) {
- * ret = drm_modeset_lock(lock, &ctx)
+ * ret = drm_modeset_lock(lock, ctx)
* if (ret == -EDEADLK) {
- * drm_modeset_backoff(&ctx);
- * goto retry;
+ * ret = drm_modeset_backoff(ctx);
+ * if (!ret)
+ * goto retry;
* }
+ * if (ret)
+ * goto out;
* }
* ... do stuff ...
- * drm_modeset_drop_locks(&ctx);
- * drm_modeset_acquire_fini(&ctx);
+ * out:
+ * drm_modeset_drop_locks(ctx);
+ * drm_modeset_acquire_fini(ctx);
*
* If all that is needed is a single modeset lock, then the &struct
* drm_modeset_acquire_ctx is not needed and the locking can be simplified
- * by passing a NULL instead of ctx in the drm_modeset_lock()
- * call and, when done, by calling drm_modeset_unlock().
+ * by passing a NULL instead of ctx in the drm_modeset_lock() call or
+ * calling drm_modeset_lock_single_interruptible(). To unlock afterwards
+ * call drm_modeset_unlock().
*
* On top of these per-object locks using &ww_mutex there's also an overall
* &drm_mode_config.mutex, for protecting everything else. Mostly this means
@@ -178,7 +183,11 @@ EXPORT_SYMBOL(drm_warn_on_modeset_not_all_locked);
/**
* drm_modeset_acquire_init - initialize acquire context
* @ctx: the acquire context
- * @flags: for future
+ * @flags: 0 or %DRM_MODESET_ACQUIRE_INTERRUPTIBLE
+ *
+ * When passing %DRM_MODESET_ACQUIRE_INTERRUPTIBLE to @flags,
+ * all calls to drm_modeset_lock() will perform an interruptible
+ * wait.
*/
void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx,
uint32_t flags)
@@ -186,6 +195,9 @@ void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx,
memset(ctx, 0, sizeof(*ctx));
ww_acquire_init(&ctx->ww_ctx, &crtc_ww_class);
INIT_LIST_HEAD(&ctx->locked);
+
+ if (flags & DRM_MODESET_ACQUIRE_INTERRUPTIBLE)
+ ctx->interruptible = true;
}
EXPORT_SYMBOL(drm_modeset_acquire_init);
@@ -261,8 +273,19 @@ static inline int modeset_lock(struct drm_modeset_lock *lock,
return ret;
}
-static int modeset_backoff(struct drm_modeset_acquire_ctx *ctx,
- bool interruptible)
+/**
+ * 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;
@@ -273,36 +296,11 @@ static int modeset_backoff(struct drm_modeset_acquire_ctx *ctx,
drm_modeset_drop_locks(ctx);
- return modeset_lock(contended, ctx, interruptible, true);
-}
-
-/**
- * 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.
- */
-void drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx)
-{
- modeset_backoff(ctx, false);
+ return modeset_lock(contended, ctx, ctx->interruptible, true);
}
EXPORT_SYMBOL(drm_modeset_backoff);
/**
- * drm_modeset_backoff_interruptible - deadlock avoidance backoff
- * @ctx: the acquire context
- *
- * Interruptible version of drm_modeset_backoff()
- */
-int drm_modeset_backoff_interruptible(struct drm_modeset_acquire_ctx *ctx)
-{
- return modeset_backoff(ctx, true);
-}
-EXPORT_SYMBOL(drm_modeset_backoff_interruptible);
-
-/**
* drm_modeset_lock_init - initialize lock
* @lock: lock to init
*/
@@ -324,14 +322,18 @@ EXPORT_SYMBOL(drm_modeset_lock_init);
* deadlock scenario has been detected and it is an error to attempt
* to take any more locks without first calling drm_modeset_backoff().
*
+ * If the @ctx is not NULL and initialized with
+ * %DRM_MODESET_ACQUIRE_INTERRUPTIBLE, this function will fail with
+ * -ERESTARTSYS when interrupted.
+ *
* If @ctx is NULL then the function call behaves like a normal,
- * non-nesting mutex_lock() call.
+ * uninterruptible non-nesting mutex_lock() call.
*/
int drm_modeset_lock(struct drm_modeset_lock *lock,
struct drm_modeset_acquire_ctx *ctx)
{
if (ctx)
- return modeset_lock(lock, ctx, false, false);
+ return modeset_lock(lock, ctx, ctx->interruptible, false);
ww_mutex_lock(&lock->mutex, NULL);
return 0;
@@ -339,21 +341,19 @@ int drm_modeset_lock(struct drm_modeset_lock *lock,
EXPORT_SYMBOL(drm_modeset_lock);
/**
- * drm_modeset_lock_interruptible - take modeset lock
+ * drm_modeset_lock_single_interruptible - take a single modeset lock
* @lock: lock to take
- * @ctx: acquire ctx
*
- * Interruptible version of drm_modeset_lock()
+ * This function behaves as drm_modeset_lock() with a NULL context,
+ * but performs interruptible waits.
+ *
+ * This function returns 0 on success, or -ERESTARTSYS when interrupted.
*/
-int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock,
- struct drm_modeset_acquire_ctx *ctx)
+int drm_modeset_lock_single_interruptible(struct drm_modeset_lock *lock)
{
- if (ctx)
- return modeset_lock(lock, ctx, true, false);
-
return ww_mutex_lock_interruptible(&lock->mutex, NULL);
}
-EXPORT_SYMBOL(drm_modeset_lock_interruptible);
+EXPORT_SYMBOL(drm_modeset_lock_single_interruptible);
/**
* drm_modeset_unlock - drop modeset lock