From nobody Tue Jun 23 23:42:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF98CC433F5 for ; Thu, 24 Feb 2022 15:24:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236173AbiBXPZC (ORCPT ); Thu, 24 Feb 2022 10:25:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234594AbiBXPY7 (ORCPT ); Thu, 24 Feb 2022 10:24:59 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C4EA722502E for ; Thu, 24 Feb 2022 07:24:29 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D1399ED1; Thu, 24 Feb 2022 07:24:28 -0800 (PST) Received: from e120937-lin.home (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 139BE3F66F; Thu, 24 Feb 2022 07:24:27 -0800 (PST) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, Cristian Marussi Subject: [PATCH] firmware: arm_scmi: Remove clear channel call on the TX channel Date: Thu, 24 Feb 2022 15:24:04 +0000 Message-Id: <20220224152404.12877-1-cristian.marussi@arm.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" On SCMI transports whose channels are based on a shared resource the TX channel area has to be acquired by the agent before placing the desired command into the channel and it will be then relinquished by the platform once the related reply has been made available into the channel. On an RX channel the logic is reversed with the platform acquiring the channel area and the agent reliquishing it once done by calling the scmi_clear_channel() helper. As a consequence, even in case of error, the agent must never try to clear a TX channel from its side: restrict the existing clear channel call on the the reply path only to delayed responses since they are indeed coming from the RX channel. Fixes: e9b21c96181c ("firmware: arm_scmi: Make .clear_channel optional") Signed-off-by: Cristian Marussi --- Applies on sudeep/for-next/scmi/fixes on top of commit 1ba603f56568 firmware: arm_scmi: Remove space in MODULE_ALIAS name --- drivers/firmware/arm_scmi/driver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi= /driver.c index d76bab3aaac4..e815b8f98739 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -652,7 +652,8 @@ static void scmi_handle_response(struct scmi_chan_info = *cinfo, =20 xfer =3D scmi_xfer_command_acquire(cinfo, msg_hdr); if (IS_ERR(xfer)) { - scmi_clear_channel(info, cinfo); + if (MSG_XTRACT_TYPE(msg_hdr) =3D=3D MSG_TYPE_DELAYED_RESP) + scmi_clear_channel(info, cinfo); return; } =20 --=20 2.17.1