From patchwork Wed May 4 16:58:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 569632 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 AAB05C38A02 for ; Wed, 4 May 2022 17:17:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357683AbiEDRTu (ORCPT ); Wed, 4 May 2022 13:19:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358236AbiEDRPr (ORCPT ); Wed, 4 May 2022 13:15:47 -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 D3A7456749 for ; Wed, 4 May 2022 09:59:31 -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 ECC05B8279C for ; Wed, 4 May 2022 16:59:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90791C385AF; Wed, 4 May 2022 16:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651683566; bh=Tude7ovqQu32WHj08xHlmW2eVvcdZfkZBmSoq4kTGSQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CaN99dRXNiEiv/ZYQIEaIBZjfw52k2j/ZlU/1ZZyaRqkzrMS1MueoSgTf2aEcICh6 HA/bByOHQKMszVMI1qdMXQiY3+LAajoRAZnuB4LeTLiguOyB10ly3B6f2fOBdWoG3y I2gSoqhRlP5gEZQBeJXcNTT7QPplJOtyEm2G5qq2YbmOpb+pL2046n9SQUvy2xpqv+ +4ESnFx5iZvgiKt4GqxcpPHUVeIOi7wuOhSXJN/eQtek7g3iA9ZARyRCP9Fjc3+xyg NRQYitWn4N8AdnFj0Mh677QgK/4pQVNn4SeMpEQNgyEi5N+7ktYi8qYwnyUCrSiSI6 1w16N+/0UZZJg== From: =?utf-8?q?Marek_Beh=C3=BAn?= To: Greg Kroah-Hartman , Sasha Levin Cc: stable@vger.kernel.org, pali@kernel.org, =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH 5.17 19/19] PCI: aardvark: Update comment about link going down after link-up Date: Wed, 4 May 2022 18:58:52 +0200 Message-Id: <20220504165852.30089-20-kabel@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220504165852.30089-1-kabel@kernel.org> References: <20220504165852.30089-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 92f4ffecc4170ce29e67a1f8d51c168c3de95fb2 upstream. Update the comment about what happens when link goes down after we have checked for link-up. If a PIO request is done while link-down, we have a serious problem. Link: https://lore.kernel.org/r/20220110015018.26359-23-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 3cbaffe892a4..5be382b19d9a 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -998,8 +998,12 @@ static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus, return false; /* - * If the link goes down after we check for link-up, nothing bad - * happens but the config access times out. + * If the link goes down after we check for link-up, we have a problem: + * if a PIO request is executed while link-down, the whole controller + * gets stuck in a non-functional state, and even after link comes up + * again, PIO requests won't work anymore, and a reset of the whole PCIe + * controller is needed. Therefore we need to prevent sending PIO + * requests while the link is down. */ if (!pci_is_root_bus(bus) && !advk_pcie_link_up(pcie)) return false;