[src/trunk]: src/sys/external/bsd/drm2/dist/drm/i915/display i915: Rework loc...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d3ed1a213403
branches:  trunk
changeset: 1028805:d3ed1a213403
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 12:04:42 2021 +0000

description:
i915: Rework locking in intel_pipe_update_start/end.

Use event_lock rather than vbl_lock for the operation; narrow the
scope of vbl_lock.

diffstat:

 sys/external/bsd/drm2/dist/drm/i915/display/intel_sprite.c |  11 ++++-------
 1 files changed, 4 insertions(+), 7 deletions(-)

diffs (66 lines):

diff -r 94afca62ecba -r d3ed1a213403 sys/external/bsd/drm2/dist/drm/i915/display/intel_sprite.c
--- a/sys/external/bsd/drm2/dist/drm/i915/display/intel_sprite.c        Sun Dec 19 12:04:33 2021 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/display/intel_sprite.c        Sun Dec 19 12:04:42 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: intel_sprite.c,v 1.4 2021/12/19 12:04:33 riastradh Exp $       */
+/*     $NetBSD: intel_sprite.c,v 1.5 2021/12/19 12:04:42 riastradh Exp $       */
 
 /*
  * Copyright © 2011 Intel Corporation
@@ -33,7 +33,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: intel_sprite.c,v 1.4 2021/12/19 12:04:33 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: intel_sprite.c,v 1.5 2021/12/19 12:04:42 riastradh Exp $");
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
@@ -122,12 +122,12 @@
                          psr_status);
 
        spin_lock(&crtc->base.dev->event_lock);
-       spin_lock(&dev_priv->drm.vbl_lock);
 
        crtc->debug.min_vbl = min;
        crtc->debug.max_vbl = max;
        trace_intel_pipe_update_start(crtc);
 
+       spin_lock(&dev_priv->drm.vbl_lock);
        DRM_SPIN_TIMED_WAIT_NOINTR_UNTIL(ret, wq, &dev_priv->drm.vbl_lock,
            timeout,
            (scanline = intel_get_crtc_scanline(crtc),
@@ -154,6 +154,7 @@
         */
        while (need_vlv_dsi_wa && scanline == vblank_start)
                scanline = intel_get_crtc_scanline(crtc);
+       spin_unlock(&dev_priv->drm.vbl_lock);
 
        crtc->debug.scanline_start = scanline;
        crtc->debug.start_vbl_time = ktime_get();
@@ -164,7 +165,6 @@
 
 irq_disable:
        spin_lock(&crtc->base.dev->event_lock);
-       spin_lock(&dev_priv->drm.vbl_lock);
 }
 
 /**
@@ -191,9 +191,7 @@
         * event outside of the critical section - the spinlock might spin for a
         * while ... */
        if (new_crtc_state->uapi.event) {
-#ifndef __NetBSD__             /* XXX locking against self */
                WARN_ON(drm_crtc_vblank_get(&crtc->base) != 0);
-#endif
 
                drm_crtc_arm_vblank_event(&crtc->base,
                                          new_crtc_state->uapi.event);
@@ -201,7 +199,6 @@
                new_crtc_state->uapi.event = NULL;
        }
 
-       spin_unlock(&dev_priv->drm.vbl_lock);
        spin_unlock(&crtc->base.dev->event_lock);
 
        if (intel_vgpu_active(dev_priv))