[src/trunk]: src/sys/external/bsd/drm2/dist/drm/i915 Narrow scope of locks in...

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

details:   https://anonhg.NetBSD.org/src/rev/4d75d3613197
branches:  trunk
changeset: 835387:4d75d3613197
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 27 14:45:11 2018 +0000

description:
Narrow scope of locks in i915 error checks to reduce deadlocks.

Not really sure why I had put some of these locks here...

diffstat:

 sys/external/bsd/drm2/dist/drm/i915/i915_irq.c |  24 ++++++++----------------
 1 files changed, 8 insertions(+), 16 deletions(-)

diffs (114 lines):

diff -r fa91e431c081 -r 4d75d3613197 sys/external/bsd/drm2/dist/drm/i915/i915_irq.c
--- a/sys/external/bsd/drm2/dist/drm/i915/i915_irq.c    Mon Aug 27 14:44:46 2018 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/i915_irq.c    Mon Aug 27 14:45:11 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: i915_irq.c,v 1.14 2018/08/27 07:14:55 riastradh Exp $  */
+/*     $NetBSD: i915_irq.c,v 1.15 2018/08/27 14:45:11 riastradh Exp $  */
 
 /* i915_irq.c -- IRQ support for the I915 -*- linux-c -*-
  */
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: i915_irq.c,v 1.14 2018/08/27 07:14:55 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: i915_irq.c,v 1.15 2018/08/27 14:45:11 riastradh Exp $");
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
@@ -1007,7 +1007,6 @@
 
 #ifdef __NetBSD__
        spin_lock_irqsave(&dev_priv->irq_lock, flags);
-       /* XXX Set a flag under the lock or push the lock out to callers.  */
        DRM_SPIN_WAKEUP_ALL(&ring->irq_queue, &dev_priv->irq_lock);
        spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
 #else
@@ -1496,7 +1495,6 @@
 
 #ifdef __NetBSD__
        spin_lock(&dev_priv->gmbus_wait_lock);
-       /* XXX Set a flag here...  */
        DRM_SPIN_WAKEUP_ALL(&dev_priv->gmbus_wait_queue,
            &dev_priv->gmbus_wait_lock);
        spin_unlock(&dev_priv->gmbus_wait_lock);
@@ -1511,7 +1509,6 @@
 
 #ifdef __NetBSD__
        spin_lock(&dev_priv->gmbus_wait_lock);
-       /* XXX Set a flag here...  */
        DRM_SPIN_WAKEUP_ALL(&dev_priv->gmbus_wait_queue,
            &dev_priv->gmbus_wait_lock);
        spin_unlock(&dev_priv->gmbus_wait_lock);
@@ -2416,10 +2413,12 @@
         * a gpu reset pending so that i915_error_work_func can acquire them).
         */
 
-       assert_spin_locked(&dev_priv->irq_lock);
 #ifdef __NetBSD__
-       for_each_ring(ring, dev_priv, i)
+       for_each_ring(ring, dev_priv, i) {
+               spin_lock(&dev_priv->irq_lock);
                DRM_SPIN_WAKEUP_ALL(&ring->irq_queue, &dev_priv->irq_lock);
+               spin_unlock(&dev_priv->irq_lock);
+       }
 
        spin_lock(&dev_priv->pending_flip_lock);
        DRM_SPIN_WAKEUP_ALL(&dev_priv->pending_flip_queue,
@@ -2537,9 +2536,7 @@
                 * Note: The wake_up also serves as a memory barrier so that
                 * waiters see the update value of the reset counter atomic_t.
                 */
-               spin_lock(&dev_priv->irq_lock);
                i915_error_wake_up(dev_priv, true);
-               spin_unlock(&dev_priv->irq_lock);
        }
 }
 
@@ -2652,8 +2649,6 @@
        va_list args;
        char error_msg[80];
 
-       assert_spin_locked(&dev_priv->irq_lock);
-
        va_start(args, fmt);
        vscnprintf(error_msg, sizeof(error_msg), fmt, args);
        va_end(args);
@@ -3047,8 +3042,6 @@
        if (!i915.enable_hangcheck)
                return;
 
-       spin_lock(&dev_priv->irq_lock);
-
        for_each_ring(ring, dev_priv, i) {
                u64 acthd;
                u32 seqno;
@@ -3063,6 +3056,7 @@
                        if (ring_idle(ring, seqno)) {
                                ring->hangcheck.action = HANGCHECK_IDLE;
 #ifdef __NetBSD__
+                               spin_lock(&dev_priv->irq_lock);
                                if (DRM_SPIN_WAITERS_P(&ring->irq_queue,
                                        &dev_priv->irq_lock)) {
                                        if (!test_and_set_bit(ring->id, &dev_priv->gpu_error.missed_irq_rings)) {
@@ -3078,6 +3072,7 @@
                                } else {
                                        busy = false;
                                }
+                               spin_unlock(&dev_priv->irq_lock);
 #else
                                if (waitqueue_active(&ring->irq_queue)) {
                                        /* Issue a wake-up to catch stuck h/w. */
@@ -3159,12 +3154,9 @@
 
        if (rings_hung) {
                i915_handle_error(dev, true, "Ring hung");
-               spin_unlock(&dev_priv->irq_lock);
                return;
        }
 
-       spin_unlock(&dev_priv->irq_lock);
-
        if (busy_count)
                /* Reset timer case chip hangs without another request
                 * being added */