[Intel-gfx] [PATCH 2/2] drm/i915: Do not enable IPS with the primary plane disabled.

[Maarten Lankhorst]

This fixes kms_universal_plane.universal-plane-pipe-A-functional.

IPS gets enabled even though the primary plane is disabled. This is
not supported, and results in warnings like below:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1707 at drivers/gpu/drm/i915/intel_display.c:1354
assert_plane.constprop.66+0x70/0xa0 [i915]()
plane A assertion failure (expected on, current off)
Modules linked in: i915
CPU: 0 PID: 1707 Comm: kms_universal_p Tainted: G        W
4.2.0-rc2-patser+ #4288
Hardware name: NUC5i7RYB,
BIOS RYBDWi35.86A.0246.2015.0309.1355 03/09/2015
 ffffffffc01d3278 ffff8800ccc37c88 ffffffff816f6e74 0000000080000000
 ffff8800ccc37cd8 ffff8800ccc37cc8 ffffffff8107bfe1 ffff8800ccc37ca8
 0000000000000000 ffff880117aa4520 ffff8800d7435388 ffff8800d5170000
Call Trace:
 [<ffffffff816f6e74>] dump_stack+0x4f/0x7b
 [<ffffffff8107bfe1>] warn_slowpath_common+0x81/0xc0
 [<ffffffff8107c061>] warn_slowpath_fmt+0x41/0x50
 [<ffffffffc016a270>] assert_plane.constprop.66+0x70/0xa0 [i915]
 [<ffffffffc0173510>] hsw_enable_ips+0x50/0x150 [i915]
 [<ffffffffc0128a63>] display_crc_ctl_write+0x623/0xbf0 [i915]
 [<ffffffff81192153>] __vfs_write+0x23/0xe0
 [<ffffffff81195334>] ? __sb_start_write+0x44/0xf0
 [<ffffffff81277718>] ? security_file_permission+0x38/0xc0
 [<ffffffff81192b34>] vfs_write+0xa4/0x190
 [<ffffffff810d73de>] ? do_setitimer+0x12e/0x220
 [<ffffffff81193741>] SyS_write+0x41/0xa0
 [<ffffffff816fdad7>] entry_SYSCALL_64_fastpath+0x12/0x6a
---[ end trace 264b7f8804a754c3 ]---

This can be fixed easily by checking primary->visible.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index caf1382116de..9abf70cb3525 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -3799,7 +3799,13 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 		 * user space can't make reliable use of the CRCs, so let's just
 		 * completely disable it.
 		 */
-		hsw_disable_ips(crtc);
+
+		if (HAS_IPS(dev) && pipe == PIPE_A) {
+			drm_modeset_lock(&crtc->base.primary->mutex, NULL);
+			if (to_intel_plane_state(crtc->base.primary->state)->visible)
+				hsw_disable_ips(crtc);
+			drm_modeset_unlock(&crtc->base.primary->mutex);
+		}
 
 		spin_lock_irq(&pipe_crc->lock);
 		kfree(pipe_crc->entries);
@@ -3843,8 +3849,12 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 			vlv_undo_pipe_scramble_reset(dev, pipe);
 		else if (IS_HASWELL(dev) && pipe == PIPE_A)
 			hsw_undo_trans_edp_pipe_A_crc_wa(dev);
-
-		hsw_enable_ips(crtc);
+		else if (HAS_IPS(dev) && pipe == PIPE_A) {
+			drm_modeset_lock(&crtc->base.primary->mutex, NULL);
+			if (to_intel_plane_state(crtc->base.primary->state)->visible)
+				hsw_enable_ips(crtc);
+			drm_modeset_unlock(&crtc->base.primary->mutex);
+		}
 	}
 
 	return 0;
-- 
2.1.0