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 89258C3A59D for ; Sat, 22 Oct 2022 07:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231372AbiJVHpk (ORCPT ); Sat, 22 Oct 2022 03:45:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231631AbiJVHop (ORCPT ); Sat, 22 Oct 2022 03:44:45 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E696859EA4; Sat, 22 Oct 2022 00:43:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8BB18B82E19; Sat, 22 Oct 2022 07:42:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 002A7C433C1; Sat, 22 Oct 2022 07:42:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666424560; bh=2PDkRAInx+5qdYpVRI+2RTNMv7awcytT6P1oXVUQ3zc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NfBsqYQb2/M3ES38czFoOsk7T1CH+5IfZjOlCvQHCZMmo7+FDaTHSqRYplithjnUG Khj/UI+tiPOs49yOlQyQHsXGtYWaxT6m3EwyozgIrTp4eDm9TBpNKO/sOBzR+VgsT3 cMIVP1qNK3E6XVoQf3JdNSQxYN9nA2xAW+90uK+I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Huisong Li , Sudeep Holla , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.19 191/717] ACPI: PCC: replace wait_for_completion() Date: Sat, 22 Oct 2022 09:21:10 +0200 Message-Id: <20221022072449.415628006@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221022072415.034382448@linuxfoundation.org> References: <20221022072415.034382448@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Huisong Li [ Upstream commit 91cefefb699120efd0a5ba345d12626b688f86ce ] Currently, the function waiting for completion of mailbox operation is 'wait_for_completion()'. The PCC method will be permanently blocked if this mailbox message fails to execute. So this patch replaces it with 'wait_for_completion_timeout()'. And set the timeout interval to an arbitrary retries on top of nominal to prevent the remote processor is slow to respond to PCC commands. Fixes: 77e2a04745ff ("ACPI: PCC: Implement OperationRegion handler for the PCC Type 3 subtype") Signed-off-by: Huisong Li Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/acpi_pcc.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c index 84f1ac416b57..16ba875e3293 100644 --- a/drivers/acpi/acpi_pcc.c +++ b/drivers/acpi/acpi_pcc.c @@ -23,6 +23,12 @@ #include +/* + * Arbitrary retries in case the remote processor is slow to respond + * to PCC commands + */ +#define PCC_CMD_WAIT_RETRIES_NUM 500 + struct pcc_data { struct pcc_mbox_chan *pcc_chan; void __iomem *pcc_comm_addr; @@ -89,6 +95,7 @@ acpi_pcc_address_space_handler(u32 function, acpi_physical_address addr, { int ret; struct pcc_data *data = region_context; + u64 usecs_lat; reinit_completion(&data->done); @@ -99,8 +106,20 @@ acpi_pcc_address_space_handler(u32 function, acpi_physical_address addr, if (ret < 0) return AE_ERROR; - if (data->pcc_chan->mchan->mbox->txdone_irq) - wait_for_completion(&data->done); + if (data->pcc_chan->mchan->mbox->txdone_irq) { + /* + * pcc_chan->latency is just a Nominal value. In reality the remote + * processor could be much slower to reply. So add an arbitrary + * amount of wait on top of Nominal. + */ + usecs_lat = PCC_CMD_WAIT_RETRIES_NUM * data->pcc_chan->latency; + ret = wait_for_completion_timeout(&data->done, + usecs_to_jiffies(usecs_lat)); + if (ret == 0) { + pr_err("PCC command executed timeout!\n"); + return AE_TIME; + } + } mbox_client_txdone(data->pcc_chan->mchan, ret); -- 2.35.1