drm/i915/reset: remove I915_RESET_MODESET flag

Since commit d59cf7bb73f3 ("drm/i915/display: Use dma_fence interfaces
instead of i915_sw_fence") we don't have anyone waiting on the
I915_RESET_MODESET bit, and there's no need for its semantics. Instead,
simply return true from intel_display_reset_prepare() to indicate that
intel_display_reset_finish() should be called.

Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/294690db3fae8fec7f356edf467e79882ed494db.1741001054.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_display_reset.c b/drivers/gpu/drm/i915/display/intel_display_reset.c
index 121679b4230f2554c6862318edb61ec5aa26d58c..acc728c75328f4f64ed72cd793bc84ced524ed34 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_reset.c
+++ b/drivers/gpu/drm/i915/display/intel_display_reset.c
@@ -27,7 +27,8 @@ bool intel_display_reset_test(struct intel_display *display)
        return display->params.force_reset_modeset_test;
 }
 
-void intel_display_reset_prepare(struct intel_display *display)
+/* returns true if intel_display_reset_finish() needs to be called */
+bool intel_display_reset_prepare(struct intel_display *display)
 {
        struct drm_i915_private *dev_priv = to_i915(display->drm);
        struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
@@ -35,17 +36,12 @@ void intel_display_reset_prepare(struct intel_display *display)
        int ret;
 
        if (!HAS_DISPLAY(display))
-               return;
+               return false;
 
        /* reset doesn't touch the display */
        if (!intel_display_reset_test(display) &&
            !gpu_reset_clobbers_display(display))
-               return;
-
-       /* We have a modeset vs reset deadlock, defensively unbreak it. */
-       set_bit(I915_RESET_MODESET, &to_gt(dev_priv)->reset.flags);
-       smp_mb__after_atomic();
-       wake_up_bit(&to_gt(dev_priv)->reset.flags, I915_RESET_MODESET);
+               return false;
 
        if (atomic_read(&display->restore.pending_fb_pin)) {
                drm_dbg_kms(display->drm,
@@ -75,7 +71,7 @@ void intel_display_reset_prepare(struct intel_display *display)
                ret = PTR_ERR(state);
                drm_err(display->drm, "Duplicating state failed with %i\n",
                        ret);
-               return;
+               return true;
        }
 
        ret = drm_atomic_helper_disable_all(display->drm, ctx);
@@ -83,11 +79,13 @@ void intel_display_reset_prepare(struct intel_display *display)
                drm_err(display->drm, "Suspending crtc's failed with %i\n",
                        ret);
                drm_atomic_state_put(state);
-               return;
+               return true;
        }
 
        display->restore.modeset_state = state;
        state->acquire_ctx = ctx;
+
+       return true;
 }
 
 void intel_display_reset_finish(struct intel_display *display)
@@ -100,10 +98,6 @@ void intel_display_reset_finish(struct intel_display *display)
        if (!HAS_DISPLAY(display))
                return;
 
-       /* reset doesn't touch the display */
-       if (!test_bit(I915_RESET_MODESET, &to_gt(i915)->reset.flags))
-               return;
-
        state = fetch_and_zero(&display->restore.modeset_state);
        if (!state)
                goto unlock;
@@ -141,6 +135,4 @@ unlock:
        drm_modeset_drop_locks(ctx);
        drm_modeset_acquire_fini(ctx);
        mutex_unlock(&display->drm->mode_config.mutex);
-
-       clear_bit_unlock(I915_RESET_MODESET, &to_gt(i915)->reset.flags);
 }

diff --git a/drivers/gpu/drm/i915/display/intel_display_reset.h b/drivers/gpu/drm/i915/display/intel_display_reset.h
index c1dd2e8d091429b27c5f55145396e4da4c39cdf3..311b5af8ca0c6e92f517ee4391af66361d5704a7 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_reset.h
+++ b/drivers/gpu/drm/i915/display/intel_display_reset.h
@@ -11,7 +11,7 @@
 struct intel_display;
 
 bool intel_display_reset_test(struct intel_display *display);
-void intel_display_reset_prepare(struct intel_display *display);
+bool intel_display_reset_prepare(struct intel_display *display);
 void intel_display_reset_finish(struct intel_display *display);
 
 #endif /* __INTEL_RESET_H__ */

diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index 2dbfb5c39d69b5964d8ea1134c7cce2aefae89da..d8425ce019dfa0e6dc6e8c9e032e425c72d13d41 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -1422,12 +1422,14 @@ static void intel_gt_reset_global(struct intel_gt *gt,
        intel_wedge_on_timeout(&w, gt, 60 * HZ) {
                struct drm_i915_private *i915 = gt->i915;
                struct intel_display *display = &i915->display;
+               bool reset_display;
 
-               intel_display_reset_prepare(display);
+               reset_display = intel_display_reset_prepare(display);
 
                intel_gt_reset(gt, engine_mask, reason);
 
-               intel_display_reset_finish(display);
+               if (reset_display)
+                       intel_display_reset_finish(display);
        }
 
        if (!test_bit(I915_WEDGED, &gt->reset.flags))
@@ -1495,7 +1497,7 @@ void intel_gt_handle_error(struct intel_gt *gt,
            intel_has_reset_engine(gt) && !intel_gt_is_wedged(gt)) {
                local_bh_disable();
                for_each_engine_masked(engine, gt, engine_mask, tmp) {
-                       BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE);
+                       BUILD_BUG_ON(I915_RESET_BACKOFF >= I915_RESET_ENGINE);
                        if (test_and_set_bit(I915_RESET_ENGINE + engine->id,
                                             &gt->reset.flags))
                                continue;

diff --git a/drivers/gpu/drm/i915/gt/intel_reset_types.h b/drivers/gpu/drm/i915/gt/intel_reset_types.h
index 80351f0a856c90380e7e8adb47c5f8644c9021db..4f5fd393af6f249d8d8e9272674db6f7944c5fd1 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_reset_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_reset_types.h
@@ -41,8 +41,7 @@ struct intel_reset {
         */
        unsigned long flags;
 #define I915_RESET_BACKOFF     0
-#define I915_RESET_MODESET     1
-#define I915_RESET_ENGINE      2
+#define I915_RESET_ENGINE      1
 #define I915_WEDGED_ON_INIT    (BITS_PER_LONG - 3)
 #define I915_WEDGED_ON_FINI    (BITS_PER_LONG - 2)
 #define I915_WEDGED            (BITS_PER_LONG - 1)