linux-kernel - [PATCH] drm/msm: mdp4: drop vblank get/put from prepare/complete

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20210715060925.7880-1-david@ixit.cz>
Date:   Thu, 15 Jul 2021 08:09:25 +0200
From:   David Heidelberg <david@...t.cz>
To:     Rob Clark <robdclark@...omium.org>, Sean Paul <sean@...rly.run>
Cc:     linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        freedreno@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        David Heidelberg <david@...t.cz>
Subject: [PATCH] drm/msm: mdp4: drop vblank get/put from prepare/complete_commit

msm_atomic is doing vblank get/put's already,
currently there no need to duplicate the effort in MDP4

Fix warning:
...
WARNING: CPU: 3 PID: 79 at drivers/gpu/drm/drm_vblank.c:1194 drm_vblank_put+0x1cc/0x1d4
...
and multiple vblank time-outs:
...
msm 5100000.mdp: vblank time out, crtc=1
...

Tested on Nexus 7 2013 (deb), LTS 5.10.50.

Introduced by: 119ecb7fd3b5 ("drm/msm/mdp4: request vblank during modeset")

Signed-off-by: David Heidelberg <david@...t.cz>
---
 drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
index a129c457c372..e5d77cef64dc 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
@@ -91,13 +91,6 @@ static void mdp4_disable_commit(struct msm_kms *kms)
 
 static void mdp4_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *state)
 {
-	int i;
-	struct drm_crtc *crtc;
-	struct drm_crtc_state *crtc_state;
-
-	/* see 119ecb7fd */
-	for_each_new_crtc_in_state(state, crtc, crtc_state, i)
-		drm_crtc_vblank_get(crtc);
 }
 
 static void mdp4_flush_commit(struct msm_kms *kms, unsigned crtc_mask)
@@ -116,12 +109,6 @@ static void mdp4_wait_flush(struct msm_kms *kms, unsigned crtc_mask)
 
 static void mdp4_complete_commit(struct msm_kms *kms, unsigned crtc_mask)
 {
-	struct mdp4_kms *mdp4_kms = to_mdp4_kms(to_mdp_kms(kms));
-	struct drm_crtc *crtc;
-
-	/* see 119ecb7fd */
-	for_each_crtc_mask(mdp4_kms->dev, crtc, crtc_mask)
-		drm_crtc_vblank_put(crtc);
 }
 
 static long mdp4_round_pixclk(struct msm_kms *kms, unsigned long rate,
-- 
2.30.2