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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 ECC4EC76191 for ; Wed, 24 Jul 2019 20:10:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B91C621852 for ; Wed, 24 Jul 2019 20:10:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563999027; bh=hdPiwWOIh86sapnLw0u7XiSoH7Kj3zi5jtTPZLDP9H0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H91J4eEHIrk16Vm4fw4pORZaepDPAyfuY8czQUrfq8hYhy/QnazmgnDLGhkhMmiP/ DsYgp6aT4owowqBDGUCeYIPAGi3ScTrAS+1+QZm75eC9dye5dhNq3lYv4PBRAfFawg Q33L30Z7BcXv4mUs5NGY9k6nkMykL0tTh33uRnnY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388835AbfGXUK0 (ORCPT ); Wed, 24 Jul 2019 16:10:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:46190 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405070AbfGXT7G (ORCPT ); Wed, 24 Jul 2019 15:59:06 -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 31F7720665; Wed, 24 Jul 2019 19:59:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998345; bh=hdPiwWOIh86sapnLw0u7XiSoH7Kj3zi5jtTPZLDP9H0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oLTX/wyZUnX+SOh7kulxi2vGuIK8ceBgLNsYU9zc851QF9X0ydaVfoYUdU0QSg6nj uUBcmE/bIQ6CqJibAaygbwqmU6z08FHqdRVlhni1snDh+hz8R4fr3zcw1iXu/TvQWH q9lMAa9BZdkmVzBfJNXK/NkOiOQXpVxYJRHAuve8= 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 5.1 332/371] PCI: qcom: Ensure that PERST is asserted for at least 100 ms Date: Wed, 24 Jul 2019 21:21:24 +0200 Message-Id: <20190724191748.756382478@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191724.382593077@linuxfoundation.org> References: <20190724191724.382593077@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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); }