From mboxrd@z Thu Jan 1 00:00:00 1970 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 8640CE95A95 for ; Mon, 9 Oct 2023 13:36:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377196AbjJINgv (ORCPT ); Mon, 9 Oct 2023 09:36:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377206AbjJINgv (ORCPT ); Mon, 9 Oct 2023 09:36:51 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B0FE99 for ; Mon, 9 Oct 2023 06:36:48 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0F4FC433C7; Mon, 9 Oct 2023 13:36:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696858608; bh=+iFhSFM6paddAXr3xH6LaBVSFFywpXPkodnbf4rgKJw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vT3byc0lV/lW24/QYvDZi4kwAp0d0Tqoi0eEYP+3/vokl6dQuHr4+GEJnUIAngpMz Fr0o74nijP/KNfhrq4aqO30NoNmorZozvv+PndYzjAeZKdVPMVbTQ32q3nofaKTSjT la6KZTtzTS5W0S5t21LeICXxKXpyiIvGR5v2khpk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Prashant Malani , Kuppuswamy Sathyanarayanan , Andy Shevchenko , Mika Westerberg , Stephen Boyd , Hans de Goede , Sasha Levin Subject: [PATCH 5.10 044/226] platform/x86: intel_scu_ipc: Check status upon timeout in ipc_wait_for_interrupt() Date: Mon, 9 Oct 2023 15:00:05 +0200 Message-ID: <20231009130127.948383919@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231009130126.697995596@linuxfoundation.org> References: <20231009130126.697995596@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Boyd [ Upstream commit 427fada620733e6474d783ae6037a66eae42bf8c ] It's possible for the completion in ipc_wait_for_interrupt() to timeout, simply because the interrupt was delayed in being processed. A timeout in itself is not an error. This driver should check the status register upon a timeout to ensure that scheduling or interrupt processing delays don't affect the outcome of the IPC return value. CPU0 SCU ---- --- ipc_wait_for_interrupt() wait_for_completion_timeout(&scu->cmd_complete) [TIMEOUT] status[IPC_STATUS_BUSY]=0 Fix this problem by reading the status bit in all cases, regardless of the timeout. If the completion times out, we'll assume the problem was that the IPC_STATUS_BUSY bit was still set, but if the status bit is cleared in the meantime we know that we hit some scheduling delay and we should just check the error bit. Cc: Prashant Malani Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Andy Shevchenko Reviewed-by: Mika Westerberg Fixes: ed12f295bfd5 ("ipc: Added support for IPC interrupt mode") Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20230913212723.3055315-3-swboyd@chromium.org Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede Signed-off-by: Sasha Levin --- drivers/platform/x86/intel_scu_ipc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c index 0b5029bca4a45..4c053c715cde0 100644 --- a/drivers/platform/x86/intel_scu_ipc.c +++ b/drivers/platform/x86/intel_scu_ipc.c @@ -249,10 +249,12 @@ static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu) { int status; - if (!wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT)) - return -ETIMEDOUT; + wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT); status = ipc_read_status(scu); + if (status & IPC_STATUS_BUSY) + return -ETIMEDOUT; + if (status & IPC_STATUS_ERR) return -EIO; -- 2.40.1