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=1793758921; b=YUTOTXFH85YU/sGCgjR0ixm0W0VnkT5HkVhRAOotGVP0gW+repVMTmKaUTevHOwEaOZg J6h5o/Lm9MEf7iQ+BuSYHZFa8AqnDe11zUHo5BtxCykCbHWmd7PstNfuNnSJxvX6F/Xeu hw2RMYauKXeJPXs0lbDNVOiSfsR8xwtWFyofWlccVULalkyxHd9FlECp2Iwe9fwJjBKm2 iwCF2PqWv4NZe8n4fzUFtn5FHgiInrRSULALOtcAPSaqO6NBUoqzj6u4NFFSqZa/CVd6K eZWUb31fLzlBVu6efj8JF5eXth71NypxghbRodfJ+SNbFeQ6TDLalLPuKN1Q1IFJbwQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793758921; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=wduqqznwFdwM4/A1mBx7ra2HodPQY2NKe2CIrZ5bscg=; b=h/xOedY9D+KIvAULNL7l7lIJ6AmmDUwTH2urSA6rFQQkvKgK4LEXs5ju5qOnmoad/+k5 MDZGnw2s94GgagSZatFLbHLwgxwOlK5L/6gzXSEJZA+J9Sz2jv9k/9Ks2alzW/Ogy6MUL Atai8CGhJyQolMLFMAxFFlxT7kDZO6Yd5TfUQcWzi3odlGDwJ5dC++AgVRo0fqgOwGMon jh/jw1mYHrQiKsHTtSiZFHMCG8Uoo78gbKlVTi0NrmU7KjL4JRkifIO7GDtZ3iXh2KsAN JtfOT20HJGqB01hbO144f77zt2gT9J4WC5TgJ3k2baTplSY3+O7Nxc4xUIlryY0w5kQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=XTJpKD8X; 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 E0F30606A32E for ; Wed, 4 Nov 2026 02:22:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=XTJpKD8X Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6074C1F00A02; Wed, 4 Nov 2026 02:22:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793758920; bh=wduqqznwFdwM4/A1mBx7ra2HodPQY2NKe2CIrZ5bscg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=XTJpKD8XiYhUcnJucKM1tCt5hljNPfgLA+n/IVj+QEZ5N7YEpr6HFMRKDQdCzDL2B gWfJPcnCQjcS0F6GAOlQDoDTbpuepuAcU5OD1msHoLQt6edYOekkpAX64xSJWDwrFj q23boZNkcxkITCqNq8s/O6jS8OFhm8WPWP7j/IDLixhjh5Hu0em/k4PsPnGtOx2adC HDWGe9fl4Y5A21KhhsKmQEMDRgm26ARg91EEprr4IKJMFMn340xGhnTXcPRhYfhBYc JdrAbrx8Q15KT9CuoF1mxvG/bIfMZ5CRs0Ja+nj7Z924+zQtuNbtgGKPbUnTDFyPWk fR2m2jWv9PYXA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] slimbus: qcom-ngd-ctrl: drop the PM runtime reference after a sync transfer Reply-To: sashiko-reviews@lists.linux.dev To: "Wentao Liang" Cc: linux-sound@vger.kernel.org In-Reply-To: <20261104021424.1468172-1-vulab@iscas.ac.cn> References: <20261104021424.1468172-1-vulab@iscas.ac.cn> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 04 Nov 2026 02:21:59 +0000 X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] slimbus: qcom-ngd-ctrl: runtime PM underflow in qcom_slim_ngd_xfer= _msg_sync() -- commit 95f275b622c76bd63160fe6491c0337ce83609c2 Author: Wentao Liang slimbus: qcom-ngd-ctrl: drop the PM runtime reference after a sync transfer This commit adds a pm_runtime_put() call on the success path of qcom_slim_ngd_xfer_msg_sync() to balance the pm_runtime_get_sync() call made at the start of the transfer. > diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-c= trl.c > index eb983b6d1815f..9bee4b376877e 100644 > --- a/drivers/slimbus/qcom-ngd-ctrl.c > +++ b/drivers/slimbus/qcom-ngd-ctrl.c > @@ -942,6 +942,9 @@ static int qcom_slim_ngd_xfer_msg_sync(struct slim_co= ntroller *ctrl, > ret =3D -ETIMEDOUT; > goto pm_put; > } > + > + pm_runtime_put(ctrl->dev); [Severity: High] Won't this underflow the runtime PM usage counter on ctrl->dev after every successful synchronous transfer? Every caller of qcom_slim_ngd_xfer_msg_sync() (qcom_slim_ngd_enable_stream(= ), qcom_slim_ngd_disable_stream(), and qcom_slim_ngd_get_laddr()) allocates a transaction ID via slim_alloc_txn_tid(ctrl, &txn). When the reply or ACK (SLIM_USR_MC_ADDR_REPLY or SLIM_USR_MC_GENERIC_ACK) arrives in qcom_slim_ngd_rx(), it invokes slim_msg_response(), which already completes txn->comp (&done) and drops the runtime PM reference: drivers/slimbus/qcom-ngd-ctrl.c:qcom_slim_ngd_rx() { ... if (mc =3D=3D SLIM_MSG_MC_REPLY_INFORMATION || mc =3D=3D SLIM_MSG_MC_REPLY_VALUE || (mc =3D=3D SLIM_USR_MC_ADDR_REPLY= && mt =3D=3D SLIM_MSG_MT_SRC_REFERRED_USER) || (mc =3D=3D SLIM_USR_MC_GENERIC_ACK && mt =3D=3D SLIM_MSG_MT_SRC_REFERRED_USER)) { slim_msg_response(&ctrl->ctrl, &buf[4], buf[3], len - 4); pm_runtime_mark_last_busy(ctrl->ctrl.dev); } } drivers/slimbus/messaging.c:slim_msg_response() { ... slim_free_txn_tid(ctrl, txn); memcpy(msg->rbuf, reply, len); if (txn->comp) complete(txn->comp); /* Remove runtime-pm vote now that response was received for TID txn */ pm_runtime_mark_last_busy(ctrl->dev); pm_runtime_put_autosuspend(ctrl->dev); } Because slim_msg_response() drops the runtime PM reference when the response is received, only the error and timeout paths in qcom_slim_ngd_xfer_msg_syn= c() (where slim_msg_response() is not reached, as handled in commit 63c60a226c9= 0) should call pm_runtime_put(ctrl->dev). Calling pm_runtime_put(ctrl->dev) on the success path releases the single pm_runtime_get_sync(ctrl->dev) referen= ce a second time, which can cause premature runtime suspension of the controll= er. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261104021424.1468= 172-1-vulab@iscas.ac.cn?part=3D1