From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793213569; b=12iQKB36XJoiHsVxMTAHexJZRgFNryBrsz9yyUCf4v0Vrc9RLzKBUWSRpt78kH/AQUQt 3n36OM/1nF9F/21vfYHSWhuKeznzWldoZCNqe6XTh/gK0n1qL+v+n1tGyqcV2zPnIDybt u5VBCydgXLVzyYzjl+ba6FYgSGpzXgnXgf6w2NvNHvVWfnNCkzTrZv342ZWawmMo+H9sH aAAc//7n3BFT7cmXVmkGbiXqHWSXyGP5lwX8e+aj36j8GbsmjuHtADJXELEaB6s5dZL96 DWYNk6YfKex/zPGsHag7Jk465Lf194xaTkWgnG1VU14FWBh9bXeGqtS0vHs1LqxQtiQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793213569; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=GzB6HrTdfav/2/oloGvwKDoea6vX7P+rmuwpRsdAQRs=; b=JrzkSts8/PONAEV0AmCPKN64pPaKS+4+E9pSXNIbhR13q2r2UfcIdE0IfuWSiyLRiMKx Z+Luy0TwX9w/+7o85ymDyCVRmkwMkD/baCnLY6vbrLjRC0GK3+pMlPukdng0v11unbUYt 12mSJl/Ce0ynBoTZYdeaAOUEbX8mbIShDDrfzUKbXxpOXWKeWCbb3ee/5YgC2rwZ+oCKp rv7ZvA4Yzxww8ox0OW7CcDIWEs1cqRIAJHPxX2IGYhHTa10L5O9ahGeXLkjJ8xwpLVTUn C8J1eaM3CwqOfwSEFFeyVH/3TVUO95W+VlQvmSwVfkOYpl9eyqNl4/yx3CUvUnfVKIQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="e+kd/1BQ"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EEEF606A31A; Wed, 28 Oct 2026 18:52:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=e+kd/1BQ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A6301F01825; Wed, 28 Oct 2026 18:52:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793213569; bh=GzB6HrTdfav/2/oloGvwKDoea6vX7P+rmuwpRsdAQRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e+kd/1BQMgU34JjhCD2owhVz4dIGYjdHzcS495sATERSUIBJ6mmRLJDzX+sVz6i79 unZxb91s2KrTkMThFEhsPCH6RL68ZlXRHNGg7NYHDh/h6M99lgsVwQuiVvJn2M1JHH OaITplyiKv4ZwYMBKMR+AkOl65yvX223MZsr97k8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paloma Arellano , Dmitry Baryshkov , Sasha Levin Subject: [PATCH 6.1 0552/1887] drm/msm/dpu: Add mutex lock in control vblank irq Date: Wed, 28 Oct 2026 17:44:08 +0100 Message-ID: <20261028170511.937676583@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paloma Arellano [ Upstream commit 45284ff733e4caf6c118aae5131eb7e7cf3eea5a ] Add a mutex lock to control vblank irq to synchronize vblank enable/disable operations happening from different threads to prevent race conditions while registering/unregistering the vblank irq callback. v4: -Removed vblank_ctl_lock from dpu_encoder_virt, so it is only a parameter of dpu_encoder_phys. -Switch from atomic refcnt to a simple int counter as mutex has now been added v3: Mistakenly did not change wording in last version. It is done now. v2: Slightly changed wording of commit message Signed-off-by: Paloma Arellano Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/571854/ Link: https://lore.kernel.org/r/20231212231101.9240-2-quic_parellan@quicinc.com Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin --- .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h | 4 ++- .../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 33 +++++++++++------ .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 35 ++++++++++++------- .../drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 1 - 4 files changed, 48 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h index f2af07d87f56f..f1f022e9dcf71 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h @@ -177,6 +177,7 @@ enum dpu_intr_idx { * @hw_wb: Hardware interface to the wb registers * @dpu_kms: Pointer to the dpu_kms top level * @cached_mode: DRM mode cached at mode_set time, acted on in enable + * @vblank_ctl_lock: Vblank ctl mutex lock to protect vblank_refcount * @enabled: Whether the encoder has enabled and running a mode * @split_role: Role to play in a split-panel configuration * @intf_mode: Interface mode @@ -207,13 +208,14 @@ struct dpu_encoder_phys { struct dpu_hw_wb *hw_wb; struct dpu_kms *dpu_kms; struct drm_display_mode cached_mode; + struct mutex vblank_ctl_lock; enum dpu_enc_split_role split_role; enum dpu_intf_mode intf_mode; enum dpu_intf intf_idx; enum dpu_wb wb_idx; spinlock_t *enc_spinlock; enum dpu_enc_enable_state enable_state; - atomic_t vblank_refcount; + int vblank_refcount; atomic_t vsync_cnt; atomic_t underrun_cnt; atomic_t pending_ctlstart_cnt; diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c index 7581e418418f1..b3cb507c052a6 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c @@ -246,7 +246,8 @@ static int dpu_encoder_phys_cmd_control_vblank_irq( return -EINVAL; } - refcount = atomic_read(&phys_enc->vblank_refcount); + mutex_lock(&phys_enc->vblank_ctl_lock); + refcount = phys_enc->vblank_refcount; /* Slave encoders don't report vblank */ if (!dpu_encoder_phys_cmd_is_master(phys_enc)) @@ -262,16 +263,24 @@ static int dpu_encoder_phys_cmd_control_vblank_irq( phys_enc->hw_pp->idx - PINGPONG_0, enable ? "true" : "false", refcount); - if (enable && atomic_inc_return(&phys_enc->vblank_refcount) == 1) - ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_RDPTR], - dpu_encoder_phys_cmd_pp_rd_ptr_irq, - phys_enc); - else if (!enable && atomic_dec_return(&phys_enc->vblank_refcount) == 0) - ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_RDPTR]); + if (enable) { + if (phys_enc->vblank_refcount == 0) + ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_RDPTR], + dpu_encoder_phys_cmd_pp_rd_ptr_irq, + phys_enc); + if (!ret) + phys_enc->vblank_refcount++; + } else if (!enable) { + if (phys_enc->vblank_refcount == 1) + ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_RDPTR]); + if (!ret) + phys_enc->vblank_refcount--; + } end: + mutex_unlock(&phys_enc->vblank_ctl_lock); if (ret) { DRM_ERROR("vblank irq err id:%u pp:%d ret:%d, enable %s/%d\n", DRMID(phys_enc->parent), @@ -287,7 +296,7 @@ static void dpu_encoder_phys_cmd_irq_control(struct dpu_encoder_phys *phys_enc, { trace_dpu_enc_phys_cmd_irq_ctrl(DRMID(phys_enc->parent), phys_enc->hw_pp->idx - PINGPONG_0, - enable, atomic_read(&phys_enc->vblank_refcount)); + enable, phys_enc->vblank_refcount); if (enable) { dpu_core_irq_register_callback(phys_enc->dpu_kms, @@ -777,6 +786,9 @@ struct dpu_encoder_phys *dpu_encoder_phys_cmd_init( phys_enc->hw_mdptop = p->dpu_kms->hw_mdp; phys_enc->intf_idx = p->intf_idx; + mutex_init(&phys_enc->vblank_ctl_lock); + phys_enc->vblank_refcount = 0; + dpu_encoder_phys_cmd_init_ops(&phys_enc->ops); phys_enc->parent = p->parent; phys_enc->parent_ops = p->parent_ops; @@ -789,7 +801,6 @@ struct dpu_encoder_phys *dpu_encoder_phys_cmd_init( for (i = 0; i < ARRAY_SIZE(phys_enc->irq); i++) phys_enc->irq[i] = -EINVAL; - atomic_set(&phys_enc->vblank_refcount, 0); atomic_set(&phys_enc->pending_kickoff_cnt, 0); atomic_set(&phys_enc->pending_ctlstart_cnt, 0); atomic_set(&cmd_enc->pending_vblank_cnt, 0); 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 4b7952c4e639f..3b45a50aa9854 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 @@ -375,7 +375,8 @@ static int dpu_encoder_phys_vid_control_vblank_irq( int ret = 0; int refcount; - refcount = atomic_read(&phys_enc->vblank_refcount); + mutex_lock(&phys_enc->vblank_ctl_lock); + refcount = phys_enc->vblank_refcount; /* Slave encoders don't report vblank */ if (!dpu_encoder_phys_vid_is_master(phys_enc)) @@ -388,18 +389,26 @@ static int dpu_encoder_phys_vid_control_vblank_irq( } DRM_DEBUG_VBL("id:%u enable=%d/%d\n", DRMID(phys_enc->parent), enable, - atomic_read(&phys_enc->vblank_refcount)); + refcount); - if (enable && atomic_inc_return(&phys_enc->vblank_refcount) == 1) - ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_VSYNC], - dpu_encoder_phys_vid_vblank_irq, - phys_enc); - else if (!enable && atomic_dec_return(&phys_enc->vblank_refcount) == 0) - ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_VSYNC]); + if (enable) { + if (phys_enc->vblank_refcount == 0) + ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_VSYNC], + dpu_encoder_phys_vid_vblank_irq, + phys_enc); + if (!ret) + phys_enc->vblank_refcount++; + } else if (!enable) { + if (phys_enc->vblank_refcount == 1) + ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_VSYNC]); + if (!ret) + phys_enc->vblank_refcount--; + } end: + mutex_unlock(&phys_enc->vblank_ctl_lock); if (ret) { DRM_ERROR("failed: id:%u intf:%d ret:%d enable:%d refcnt:%d\n", DRMID(phys_enc->parent), @@ -607,7 +616,7 @@ static void dpu_encoder_phys_vid_irq_control(struct dpu_encoder_phys *phys_enc, trace_dpu_enc_phys_vid_irq_ctrl(DRMID(phys_enc->parent), phys_enc->hw_intf->idx - INTF_0, enable, - atomic_read(&phys_enc->vblank_refcount)); + phys_enc->vblank_refcount); if (enable) { ret = dpu_encoder_phys_vid_control_vblank_irq(phys_enc, true); @@ -703,6 +712,9 @@ struct dpu_encoder_phys *dpu_encoder_phys_vid_init( DPU_DEBUG_VIDENC(phys_enc, "\n"); + mutex_init(&phys_enc->vblank_ctl_lock); + phys_enc->vblank_refcount = 0; + dpu_encoder_phys_vid_init_ops(&phys_enc->ops); phys_enc->parent = p->parent; phys_enc->parent_ops = p->parent_ops; @@ -713,7 +725,6 @@ struct dpu_encoder_phys *dpu_encoder_phys_vid_init( for (i = 0; i < ARRAY_SIZE(phys_enc->irq); i++) phys_enc->irq[i] = -EINVAL; - atomic_set(&phys_enc->vblank_refcount, 0); atomic_set(&phys_enc->pending_kickoff_cnt, 0); init_waitqueue_head(&phys_enc->pending_kickoff_wq); phys_enc->enable_state = DPU_ENC_DISABLED; diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c index fd5f9d04f81e6..462fa58c660df 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c @@ -735,7 +735,6 @@ struct dpu_encoder_phys *dpu_encoder_phys_wb_init( phys_enc->irq[i] = -EINVAL; atomic_set(&phys_enc->pending_kickoff_cnt, 0); - atomic_set(&phys_enc->vblank_refcount, 0); wb_enc->wb_done_timeout_cnt = 0; init_waitqueue_head(&phys_enc->pending_kickoff_wq); -- 2.53.0