From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AC91A1AAE28; Sat, 17 Oct 2026 17:22:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792257735; cv=none; b=N09O11D/uMUCUu+Tq1oerXpBNt9491uL1yAOagrGhqyu7bb9F9bGLxg4bT/S2oDCQPm+8P7KkbERh2eZcK8+gb3weTpcNqLXSHj/V6uJjPo1v4vGlJM/8CHE/gnKP6odeULTQ3YHximunbdr0gV4ZmTMgaoUQ+Le3wHaeNGniLA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792257735; c=relaxed/simple; bh=iiybtnL+bGBlCnsSh7uEg4ZDY74bYPZFtu6tAjyNnas=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=p8zqhMewP6WxvxKyB9oXwPqCf4LynSBjY/wKVvUL5skNmTaGRpcWu2t8aXTe444NfplukKevPBDi+GVasQ6D3Op+/xr51VGqhZJKlsmFFP1I4/aH7e5Ong42hQQ/G6wKQ3lPhuE4OJDdzC7yC7s5ycarupOgpGYQtHqLqOntV/M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Z+QsfToW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Z+QsfToW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7C6F1F000C4; Sat, 17 Oct 2026 17:22:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792257733; bh=kGefcS15k5afXIWVGE34U90PX8bzLIgSvuDZ+UXsFss=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Z+QsfToWYgeZmXtziAK71RyIBaWNZOilSZhXCXN+RWr1QYPw54r6rz7DmIlk7olAI nj7QZOBDILGrDwSdKboz43NF5yOyHG/zRyrLw3TSnYEH07uSYWq25HOlBdbsluPnbj gAlhYoxH5FI6YD0KBgz2ssFR/L62Q7e66puKW+Vc= 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 6.6 0616/1674] drm/msm/dpu: Add mutex lock in control vblank irq Date: Sat, 17 Oct 2026 17:48:08 +0200 Message-ID: <20261017160446.889113301@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-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 --- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 1 - .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h | 4 ++- .../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 32 ++++++++++++------ .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 33 ++++++++++++------- 4 files changed, 47 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index 8c630615ed928..dcf8127b9b6ef 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -2541,7 +2541,6 @@ void dpu_encoder_phys_init(struct dpu_encoder_phys *phys_enc, phys_enc->enc_spinlock = p->enc_spinlock; phys_enc->enable_state = DPU_ENC_DISABLED; - atomic_set(&phys_enc->vblank_refcount, 0); atomic_set(&phys_enc->pending_kickoff_cnt, 0); atomic_set(&phys_enc->pending_ctlstart_cnt, 0); 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 ddfed280597d8..461e8c20cce81 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h @@ -154,6 +154,7 @@ 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 @@ -182,11 +183,12 @@ 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; 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 fd2400c4665d2..6ec75f215d2e5 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 @@ -252,7 +252,8 @@ 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)) @@ -268,16 +269,24 @@ 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_te_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_te_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), @@ -293,7 +302,7 @@ 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, @@ -735,6 +744,9 @@ struct dpu_encoder_phys *dpu_encoder_phys_cmd_init(struct drm_device *dev, dpu_encoder_phys_init(phys_enc, p); + mutex_init(&phys_enc->vblank_ctl_lock); + phys_enc->vblank_refcount = 0; + dpu_encoder_phys_cmd_init_ops(&phys_enc->ops); phys_enc->intf_mode = INTF_MODE_CMD; cmd_enc->stream_sel = 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 2cda9bbf68f96..da753f2dbd26d 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 @@ -373,7 +373,8 @@ 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)) @@ -386,18 +387,26 @@ 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), @@ -621,7 +630,7 @@ 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); @@ -714,6 +723,8 @@ struct dpu_encoder_phys *dpu_encoder_phys_vid_init(struct drm_device *dev, DPU_DEBUG_VIDENC(phys_enc, "\n"); dpu_encoder_phys_init(phys_enc, p); + mutex_init(&phys_enc->vblank_ctl_lock); + phys_enc->vblank_refcount = 0; dpu_encoder_phys_vid_init_ops(&phys_enc->ops); phys_enc->intf_mode = INTF_MODE_VIDEO; -- 2.53.0