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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9ADD6C76191 for ; Wed, 24 Jul 2019 20:24:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6085B2081B for ; Wed, 24 Jul 2019 20:24:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563999888; bh=hdPiwWOIh86sapnLw0u7XiSoH7Kj3zi5jtTPZLDP9H0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vBpRvJvktGELrmTQmF7m5851xw39zuEeyyX2jsMfsFKRrRK3E9yb0JaTcfCkGXAKF KBnBKyVtDRkSQ5FE8OAuHcxYZIB3KFuxqqwwG1A+FlOpaV5bitUWbDDabt0UNLzAx7 sz205E5ZuIxQQpWlf6HARgFPu7KQ8O/wEyKY2bhc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390029AbfGXTkd (ORCPT ); Wed, 24 Jul 2019 15:40:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:41740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390010AbfGXTka (ORCPT ); Wed, 24 Jul 2019 15:40:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BDD1B20665; Wed, 24 Jul 2019 19:40:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997229; bh=hdPiwWOIh86sapnLw0u7XiSoH7Kj3zi5jtTPZLDP9H0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xqwklLOxfDDk/iHBwunCY4qXfr5pSJ5H8U4s08P2JE5j5ObzASVNwKDQcQE/WGGa0 KjY/AzSP2AhpRO2+LnFJEckupQx2u0TDXCECH5asUCLKUTy3A/VBOoNnLGo9v76TF4 zH7FrK/Sykg3rcEVC8fDrFPcnkG7Img8DXvbdAOg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Niklas Cassel , Lorenzo Pieralisi , Stanimir Varbanov Subject: [PATCH 5.2 366/413] PCI: qcom: Ensure that PERST is asserted for at least 100 ms Date: Wed, 24 Jul 2019 21:20:57 +0200 Message-Id: <20190724191801.598390481@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191735.096702571@linuxfoundation.org> References: <20190724191735.096702571@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Niklas Cassel commit 64adde31c8e996a6db6f7a1a4131180e363aa9f2 upstream. Currently, there is only a 1 ms sleep after asserting PERST. Reading the datasheets for different endpoints, some require PERST to be asserted for 10 ms in order for the endpoint to perform a reset, others require it to be asserted for 50 ms. Several SoCs using this driver uses PCIe Mini Card, where we don't know what endpoint will be plugged in. The PCI Express Card Electromechanical Specification r2.0, section 2.2, "PERST# Signal" specifies: "On power up, the deassertion of PERST# is delayed 100 ms (TPVPERL) from the power rails achieving specified operating limits." Add a sleep of 100 ms before deasserting PERST, in order to ensure that we are compliant with the spec. Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Signed-off-by: Niklas Cassel Signed-off-by: Lorenzo Pieralisi Acked-by: Stanimir Varbanov Cc: stable@vger.kernel.org # 4.5+ Signed-off-by: Greg Kroah-Hartman --- drivers/pci/controller/dwc/pcie-qcom.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -178,6 +178,8 @@ static void qcom_ep_reset_assert(struct static void qcom_ep_reset_deassert(struct qcom_pcie *pcie) { + /* Ensure that PERST has been asserted for at least 100 ms */ + msleep(100); gpiod_set_value_cansleep(pcie->reset, 0); usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500); }