[PATCH i-g-t] [i-g-t] tests/kms_cursor_legacy: Restructure cursor_vs_flip

[Vidya Srinivas]

Current code causes reboot issues on some devices during
execution of cursor_vs_flip. Change the code structure
similar to flip_vs_cursor

Signed-off-by: Vidya Srinivas <vidya.srinivas at intel.com>
---
 tests/kms_cursor_legacy.c | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/tests/kms_cursor_legacy.c b/tests/kms_cursor_legacy.c
index 0017659d4..962b2b38b 100644
--- a/tests/kms_cursor_legacy.c
+++ b/tests/kms_cursor_legacy.c
@@ -1345,19 +1345,18 @@ static void cursor_vs_flip(igt_display_t *display, enum flip_test mode, int nloo
 	struct igt_fb fb_info, cursor_fb, cursor_fb2, argb_fb;
 	unsigned vblank_start, vblank_last;
 	volatile unsigned long *shared;
-	long target;
+	int target, cpu;
 	enum pipe pipe;
 	igt_output_t *output;
 	uint32_t vrefresh;
 	int fail_count;
 	igt_plane_t *cursor;
+	cpu_set_t mask, oldmask;
+	unsigned long count = 0;
 
 	if (mode >= flip_test_atomic)
 		igt_require(display->is_atomic);
 
-	shared = mmap(NULL, PAGE_SIZE, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
-	igt_assert(shared != MAP_FAILED);
-
 	pipe = find_connected_pipe(display, false, &output);
 	igt_require(output);
 
@@ -1376,19 +1375,37 @@ static void cursor_vs_flip(igt_display_t *display, enum flip_test mode, int nloo
 
 	igt_display_commit2(display, display->is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
 
-	target = get_cursor_updates_per_vblank(display, pipe, &arg[0]);
+	if (nloops)
+		target = get_cursor_updates_per_vblank(display, pipe, &arg[0]);
+	else
+		target = 1;
 
 	fail_count = 0;
 
 	for (int i = 0; i < nloops; i++) {
+		shared = mmap(NULL, PAGE_SIZE, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+		igt_assert(shared != MAP_FAILED);
+		cpu = sched_getcpu();
+		igt_assert(cpu >= 0);
+
+		CPU_ZERO(&mask);
+		CPU_SET(cpu, &mask);
+		sched_getaffinity(0, sizeof(oldmask), &oldmask);
+		sched_setaffinity(0, sizeof(mask), &mask);
+
 		shared[0] = 0;
+
 		igt_fork(child, 1) {
-			unsigned long count = 0;
+			struct sched_param parm = { .sched_priority = 0 };
+
+			igt_assert(sched_setscheduler(0, SCHED_IDLE, &parm) == 0);
+
 			while (!shared[0]) {
 				do_ioctl(display->drm_fd, DRM_IOCTL_MODE_CURSOR, &arg[i & 1]);
+				sched_yield();
+				igt_debug("child: %lu cursor updates\n", count);
 				count++;
 			}
-			igt_debug("child: %lu cursor updates\n", count);
 			shared[0] = count;
 		}
 
@@ -1428,6 +1445,8 @@ static void cursor_vs_flip(igt_display_t *display, enum flip_test mode, int nloo
 				     shared[0], vrefresh / 2,
 				     vrefresh*target, vrefresh*target / 2);
 		}
+		munmap((void *)shared, PAGE_SIZE);
+		sched_setaffinity(0, sizeof(oldmask), &oldmask);
 	}
 
 	igt_assert_f(fail_count == 0,
@@ -1443,7 +1462,6 @@ static void cursor_vs_flip(igt_display_t *display, enum flip_test mode, int nloo
 
 	igt_remove_fb(display->drm_fd, &fb_info);
 	igt_remove_fb(display->drm_fd, &cursor_fb);
-	munmap((void *)shared, PAGE_SIZE);
 	if (argb_fb.gem_handle)
 		igt_remove_fb(display->drm_fd, &argb_fb);
 	if (cursor_fb2.gem_handle)
-- 
2.33.0