drm/fb-helper: Stop using mode_config.mutex for internals

Those are now all protected using fb_helper->lock.

v2: We still need to hold mode_config.mutex right around calling
connector->fill_modes.

v3: I forgot to hold mode_config.mutex while looking at
connector->status and the mode list. Also, we need to patch up the
i915 ->initial_config callback to grab the locks it needs to inspect
the modeset state recovered from the fw.

v4: Don't reorder the probe too much (Ville).

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170705045629.31265-1-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c5bf37f..5d3d776 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -106,7 +106,7 @@ static DEFINE_MUTEX(kernel_fb_helper_lock);
  */
 
 #define drm_fb_helper_for_each_connector(fbh, i__) \
-       for (({ lockdep_assert_held(&(fbh)->dev->mode_config.mutex); }), \
+       for (({ lockdep_assert_held(&(fbh)->lock); }), \
             i__ = 0; i__ < (fbh)->connector_count; i__++)
 
 static int __drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
@@ -120,7 +120,6 @@ static int __drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
                return 0;
 
        lockdep_assert_held(&fb_helper->lock);
-       lockdep_assert_held(&fb_helper->dev->mode_config.mutex);
 
        count = fb_helper->connector_count + 1;
 
@@ -152,11 +151,7 @@ int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
        int err;
 
        mutex_lock(&fb_helper->lock);
-       mutex_lock(&fb_helper->dev->mode_config.mutex);
-
        err = __drm_fb_helper_add_one_connector(fb_helper, connector);
-
-       mutex_unlock(&fb_helper->dev->mode_config.mutex);
        mutex_unlock(&fb_helper->lock);
 
        return err;
@@ -188,7 +183,6 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
                return 0;
 
        mutex_lock(&fb_helper->lock);
-       mutex_lock(&dev->mode_config.mutex);
        drm_connector_list_iter_begin(dev, &conn_iter);
        drm_for_each_connector_iter(connector, &conn_iter) {
                ret = __drm_fb_helper_add_one_connector(fb_helper, connector);
@@ -210,7 +204,6 @@ fail:
        fb_helper->connector_count = 0;
 out:
        drm_connector_list_iter_end(&conn_iter);
-       mutex_unlock(&dev->mode_config.mutex);
        mutex_unlock(&fb_helper->lock);
 
        return ret;
@@ -253,11 +246,7 @@ int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
        int err;
 
        mutex_lock(&fb_helper->lock);
-       mutex_lock(&fb_helper->dev->mode_config.mutex);
-
        err = __drm_fb_helper_remove_one_connector(fb_helper, connector);
-
-       mutex_unlock(&fb_helper->dev->mode_config.mutex);
        mutex_unlock(&fb_helper->lock);
 
        return err;
@@ -1879,12 +1868,11 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
 EXPORT_SYMBOL(drm_fb_helper_fill_var);
 
 static int drm_fb_helper_probe_connector_modes(struct drm_fb_helper *fb_helper,
-                                              uint32_t maxX,
-                                              uint32_t maxY)
+                                               uint32_t maxX,
+                                               uint32_t maxY)
 {
        struct drm_connector *connector;
-       int count = 0;
-       int i;
+       int i, count = 0;
 
        drm_fb_helper_for_each_connector(fb_helper, i) {
                connector = fb_helper->connector_info[i]->connector;
@@ -2282,12 +2270,8 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
        int i;
 
        DRM_DEBUG_KMS("\n");
-       if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0)
-               DRM_DEBUG_KMS("No connectors reported connected with modes\n");
-
        /* prevent concurrent modification of connector_count by hotplug */
        lockdep_assert_held(&fb_helper->lock);
-       lockdep_assert_held(&fb_helper->dev->mode_config.mutex);
 
        crtcs = kcalloc(fb_helper->connector_count,
                        sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
@@ -2302,6 +2286,9 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
                goto out;
        }
 
+       mutex_lock(&fb_helper->dev->mode_config.mutex);
+       if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0)
+               DRM_DEBUG_KMS("No connectors reported connected with modes\n");
        drm_enable_connectors(fb_helper, enabled);
 
        if (!(fb_helper->funcs->initial_config &&
@@ -2323,6 +2310,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
 
                drm_pick_crtcs(fb_helper, crtcs, modes, 0, width, height);
        }
+       mutex_unlock(&fb_helper->dev->mode_config.mutex);
 
        /* need to set the modesets up here for use later */
        /* fill out the connector<->crtc mappings into the modesets */
@@ -2414,12 +2402,10 @@ int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
                return 0;
 
        mutex_lock(&fb_helper->lock);
-       mutex_lock(&dev->mode_config.mutex);
        drm_setup_crtcs(fb_helper,
                        dev->mode_config.max_width,
                        dev->mode_config.max_height);
        ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
-       mutex_unlock(&dev->mode_config.mutex);
        mutex_unlock(&fb_helper->lock);
        if (ret)
                return ret;
@@ -2482,10 +2468,7 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 
        DRM_DEBUG_KMS("\n");
 
-       mutex_lock(&dev->mode_config.mutex);
        drm_setup_crtcs(fb_helper, fb_helper->fb->width, fb_helper->fb->height);
-
-       mutex_unlock(&dev->mode_config.mutex);
        mutex_unlock(&fb_helper->lock);
 
        drm_fb_helper_set_par(fb_helper->fbdev);

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 05d043e..8099574 100644 (file)
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -836,7 +836,7 @@ static void send_vblank_event(struct drm_device *dev,
  * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an
  * atomic commit must ensure that the next vblank happens at exactly the same
  * time as the atomic commit is committed to the hardware. This function itself
- * does **not** protect again the next vblank interrupt racing with either this
+ * does **not** protect against the next vblank interrupt racing with either this
  * function call or the atomic commit operation. A possible sequence could be:
  *
  * 1. Driver commits new hardware state into vblank-synchronized registers.

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 03347c6..460ca0b 100644 (file)
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -352,14 +352,20 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
        unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG);
        int i, j;
        bool *save_enabled;
-       bool fallback = true;
+       bool fallback = true, ret = true;
        int num_connectors_enabled = 0;
        int num_connectors_detected = 0;
+       struct drm_modeset_acquire_ctx ctx;
 
        save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL);
        if (!save_enabled)
                return false;
 
+       drm_modeset_acquire_init(&ctx, 0);
+
+       while (drm_modeset_lock_all_ctx(fb_helper->dev, &ctx) != 0)
+               drm_modeset_backoff(&ctx);
+
        memcpy(save_enabled, enabled, count);
        mask = GENMASK(count - 1, 0);
        conn_configured = 0;
@@ -509,12 +515,14 @@ retry:
 bail:
                DRM_DEBUG_KMS("Not using firmware configuration\n");
                memcpy(enabled, save_enabled, count);
-               kfree(save_enabled);
-               return false;
+               ret = false;
        }
 
+       drm_modeset_drop_locks(&ctx);
+       drm_modeset_acquire_fini(&ctx);
+
        kfree(save_enabled);
-       return true;
+       return ret;
 }
 
 static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {