From nobody Mon Sep 15 17:38:53 2025 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 C555EC46467 for ; Wed, 11 Jan 2023 13:46:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232874AbjAKNqn (ORCPT ); Wed, 11 Jan 2023 08:46:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234223AbjAKNqV (ORCPT ); Wed, 11 Jan 2023 08:46:21 -0500 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE159631F for ; Wed, 11 Jan 2023 05:45:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1673444758; x=1704980758; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=M0K6BPFNHtGJsQXxOTjDHE/+MPRCH1csScxb1OhpftI=; b=IY+z7nnF75FxHIjyUCWASBE/iT77zAxfQ0+7+RFL/5igR8V1dMYlB7/e nXgokxFI3ZEMwwhGHnWtKo6QWffS1+uj76NYfJ3tutXMvvK6xisYHXGY1 iZLIR/lgcm7wnFfbhNdY7slRIngY3zI3xpqV2ebzQj3WpzokZa/VrDgZr Mfsvpqa7+qAaztSIkuwXyB988BAJQnULiNXdneMAEAfXH63eTHDRa2Kue 80Z6MteiZYicH3rBRV4C8E+d4iX0NwfNNQwiHJe6FFz+VqfVwzOClVVuN 1c5tRlVDhnaVagmeiBpnUQdF+ih9SjiMw9QZ6FFvmTw/4rTLONSCTLGXB A==; X-IronPort-AV: E=Sophos;i="5.96,317,1665471600"; d="scan'208";a="207325811" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa1.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 11 Jan 2023 06:45:58 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16; Wed, 11 Jan 2023 06:45:57 -0700 Received: from wendy.microchip.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2507.16 via Frontend Transport; Wed, 11 Jan 2023 06:45:56 -0700 From: Conor Dooley To: Jassi Brar CC: Conor Dooley , Daire McNamara , , Subject: [PATCH v1 7/7] soc: microchip: mpfs: handle timeouts and failed services differently Date: Wed, 11 Jan 2023 13:45:13 +0000 Message-ID: <20230111134513.2495510-8-conor.dooley@microchip.com> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230111134513.2495510-1-conor.dooley@microchip.com> References: <20230111134513.2495510-1-conor.dooley@microchip.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The system controller will only deliver an interrupt if a service succeeds. This leaves us in the unfortunate position with current code where there is no way to differentiate between a legitimate timeout where the service has not completed & where it has completed, but failed. mbox_send_message() has its own completion, and it will time out of the system controller does not lower the busy flag. In this case, a timeout has occurred and the error can be propagated back to the caller. If the busy flag is lowered, but no interrupt has arrived to trigger the rx callback, the service can be deemed to have failed. Report EBADMSG in this case so that callers can differentiate. Signed-off-by: Conor Dooley --- drivers/soc/microchip/mpfs-sys-controller.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/soc/microchip/mpfs-sys-controller.c b/drivers/soc/micr= ochip/mpfs-sys-controller.c index 4aadd05769d2..75422db75fe5 100644 --- a/drivers/soc/microchip/mpfs-sys-controller.c +++ b/drivers/soc/microchip/mpfs-sys-controller.c @@ -41,14 +41,25 @@ int mpfs_blocking_transaction(struct mpfs_sys_controlle= r *sys_controller, struct reinit_completion(&sys_controller->c); =20 ret =3D mbox_send_message(sys_controller->chan, msg); - if (ret < 0) + if (ret < 0) { + dev_warn(sys_controller->client.dev, + "MPFS sys controller service timeout\n"); goto out; + } =20 ret =3D 0; /* mbox_send_message returns postitive integers on success */ + + /* + * Unfortunately, the system controller will only deliver an interrupt + * if a service succeeds. mbox_send_message() will block until the busy + * flag is gone. If the busy flag is gone but no interrupt has arrived + * to trigger the rx callback then the service can be deemed to have + * failed. + */ if (!wait_for_completion_timeout(&sys_controller->c, timeout)) { - ret =3D -ETIMEDOUT; + ret =3D -EBADMSG; dev_warn(sys_controller->client.dev, - "MPFS sys controller transaction timeout\n"); + "MPFS sys controller service failed\n"); } =20 out: @@ -106,6 +117,7 @@ static int mpfs_sys_controller_probe(struct platform_de= vice *pdev) sys_controller->client.dev =3D dev; sys_controller->client.rx_callback =3D rx_callback; sys_controller->client.tx_block =3D 1U; + sys_controller->client.tx_tout =3D msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT= _MS); =20 sys_controller->chan =3D mbox_request_channel(&sys_controller->client, 0); if (IS_ERR(sys_controller->chan)) { --=20 2.39.0