From:   Vinod Polimera <quic_vpolimer@quicinc.com>
To:     <dri-devel@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        <freedreno@lists.freedesktop.org>, <devicetree@vger.kernel.org>
CC:     Vinod Polimera <quic_vpolimer@quicinc.com>,
        <linux-kernel@vger.kernel.org>, <robdclark@gmail.com>,
        <dianders@chromium.org>, <swboyd@chromium.org>,
        <quic_kalyant@quicinc.com>, <dmitry.baryshkov@linaro.org>,
        <quic_khsieh@quicinc.com>, <quic_vproddut@quicinc.com>,
        <quic_bjorande@quicinc.com>, <quic_abhinavk@quicinc.com>,
        <quic_sbillaka@quicinc.com>
Subject: [PATCH v14 06/14] drm/msm/disp/dpu: wait for extra vsync till timing engine status is disabled
Date:   Thu, 2 Mar 2023 22:03:09 +0530
Message-ID: <1677774797-31063-7-git-send-email-quic_vpolimer@quicinc.com>
In-Reply-To: <1677774797-31063-1-git-send-email-quic_vpolimer@quicinc.com>
References: <1677774797-31063-1-git-send-email-quic_vpolimer@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

There can be a race between timing gen disable and vblank irq. The
wait post timing gen disable may return early but intf disable sequence
might not be completed. Ensure that, intf status is disabled before
we retire the function.

Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c    | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
index 48c4810..0396084 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
@@ -523,6 +523,7 @@ static void dpu_encoder_phys_vid_disable(struct dpu_encoder_phys *phys_enc)
 {
 	unsigned long lock_flags;
 	int ret;
+	struct intf_status intf_status = {0};
 
 	if (!phys_enc->parent || !phys_enc->parent->dev) {
 		DPU_ERROR("invalid encoder/device\n");
@@ -567,6 +568,26 @@ static void dpu_encoder_phys_vid_disable(struct dpu_encoder_phys *phys_enc)
 		}
 	}
 
+	if (phys_enc->hw_intf && phys_enc->hw_intf->ops.get_status)
+		phys_enc->hw_intf->ops.get_status(phys_enc->hw_intf, &intf_status);
+
+	/*
+	 * Wait for a vsync if timing en status is on after timing engine
+	 * is disabled.
+	 */
+	if (intf_status.is_en && dpu_encoder_phys_vid_is_master(phys_enc)) {
+		spin_lock_irqsave(phys_enc->enc_spinlock, lock_flags);
+		dpu_encoder_phys_inc_pending(phys_enc);
+		spin_unlock_irqrestore(phys_enc->enc_spinlock, lock_flags);
+		ret = dpu_encoder_phys_vid_wait_for_vblank(phys_enc);
+		if (ret) {
+			atomic_set(&phys_enc->pending_kickoff_cnt, 0);
+			DRM_ERROR("wait disable failed: id:%u intf:%d ret:%d\n",
+				  DRMID(phys_enc->parent),
+				  phys_enc->hw_intf->idx - INTF_0, ret);
+		}
+	}
+
 	phys_enc->enable_state = DPU_ENC_DISABLED;
 }
 
-- 
2.7.4