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 62D40E7C4EC for ; Wed, 4 Oct 2023 18:25:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244121AbjJDSZq (ORCPT ); Wed, 4 Oct 2023 14:25:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244177AbjJDSZp (ORCPT ); Wed, 4 Oct 2023 14:25:45 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C317C4 for ; Wed, 4 Oct 2023 11:25:42 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B12F2C433C9; Wed, 4 Oct 2023 18:25:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696443942; bh=B1C8ErroQWswcGvww9iM+7pF7H6DFo7mP0Lb7DgLEmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RaEqpqU2P2zjqzQ3n0GmZ9flmbhBzLMqIT8oJpHCQTeEJztRyU9ZVweV6BCP4JboD Z6pGf5Vlt8TxSFO1GXrxmkest+3AIbRJ3cYc+R3sDYeew9k35KDCLROIy2wCNcSMTf mpaHIXrOZ9ENv5udch17CIaG9SuecoVKi5tZSTf8= 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 6.5 074/321] platform/x86: intel_scu_ipc: Check status upon timeout in ipc_wait_for_interrupt() Date: Wed, 4 Oct 2023 19:53:39 +0200 Message-ID: <20231004175232.633775631@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175229.211487444@linuxfoundation.org> References: <20231004175229.211487444@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 6.5-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 4c774ee8bb1bb..299c15312acb8 100644 --- a/drivers/platform/x86/intel_scu_ipc.c +++ b/drivers/platform/x86/intel_scu_ipc.c @@ -248,10 +248,12 @@ 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