drm/i915: Fix page fault handler failure

... when __wait_seqno() is interrupted by a signal. In this case,
__wait_seqno() returns -ERESTARTSYS. Like we already do in drm_ioctl(),
we need to convert this error to a common code such as -EINTR, so the
page fault handler is restarted.

Reported by:	Frederic Chardon <chardon.frederic@gmail.com>
Tested by:	Frederic Chardon <chardon.frederic@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/sys/dev/drm2/i915/i915_gem.c b/sys/dev/drm2/i915/i915_gem.c
index 625c8a67c175..7789e360326e 100644
--- a/sys/dev/drm2/i915/i915_gem.c
+++ b/sys/dev/drm2/i915/i915_gem.c
@@ -1619,6 +1619,13 @@ out:
 	KASSERT(ret != 0, ("i915_gem_pager_fault: wrong return"));
 	CTR4(KTR_DRM, "fault_fail %p %jx %x err %d", gem_obj, offset, prot,
 	    -ret);
+	if (ret == -ERESTARTSYS) {
+		/*
+		 * NOTE Linux<->FreeBSD: Convert Linux' -ERESTARTSYS to
+		 * the more common -EINTR, so the page fault is retried.
+		 */
+		ret = -EINTR;
+	}
 	if (ret == -EAGAIN || ret == -EIO || ret == -EINTR) {
 		kern_yield(PRI_USER);
 		goto retry;