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 76294C433EF for ; Mon, 9 May 2022 12:18:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234262AbiEIMWn (ORCPT ); Mon, 9 May 2022 08:22:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234247AbiEIMWk (ORCPT ); Mon, 9 May 2022 08:22:40 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49E57193223; Mon, 9 May 2022 05:18:39 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: kholk11) with ESMTPSA id 1F08E1F43BA5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1652098717; bh=/ElfDQ7Z0+LPIiP82VOSR/z6/oF6F1kOGCw4zRzqtM0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SFNDAWZ+B9j/a0+7UlWwDPvBoOHehJzS5iBQT9zXO/qZkN3if5DX5LWbW2aFUP5vQ UcwkEtUhhnJTuuOXAHUCQdF1D8NBNFVLuBHz+xv2PpuOdxhRV38LsVehwOT8P2YEOR 2jd9vsL03Pc5W0D/lKKlY3CeNu80kOd+9kJZ1hxq0xEr3g3cxZ1lDOB5SxY3WiQc42 uhoq5OdtWrv6zvXO3G0M25Qk2DG/TcJodNMPDvUKPRSf8Rg2OAmQ4Pbs6IAEkwMbcO g4vghNiQAExBdJUJGc4Ci4AYscSw0+Cps3vuO50jOxVQKb78S1jAAuKlMKuJiRadOb rLNLAKw/Bmo8w== Message-ID: Date: Mon, 9 May 2022 14:18:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH] PCI: mediatek-gen3: Assert resets to ensure expected init state Content-Language: en-US To: ryder.lee@mediatek.com Cc: jianjun.wang@mediatek.com, lorenzo.pieralisi@arm.com, robh@kernel.org, kw@linux.com, bhelgaas@google.com, p.zabel@pengutronix.de, matthias.bgg@gmail.com, linux-pci@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel@collabora.com, nfraprado@collabora.com References: <20220404144858.92390-1-angelogioacchino.delregno@collabora.com> From: AngeloGioacchino Del Regno In-Reply-To: <20220404144858.92390-1-angelogioacchino.delregno@collabora.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 04/04/22 16:48, AngeloGioacchino Del Regno ha scritto: > The controller may have been left out of reset by the bootloader, > in which case, before the powerup sequence, the controller will be > found preconfigured with values that were set before booting the > kernel: this produces a controller failure, with the result of > a failure during the mtk_pcie_startup_port() sequence as the PCIe > link never gets up. > > To ensure that we get a clean start in an expected state, assert > both the PHY and MAC resets before executing the controller > power-up sequence. > > Fixes: d3bf75b579b9 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192") > Signed-off-by: AngeloGioacchino Del Regno Friendly ping for an important fix :-) Regards, Angelo > --- > drivers/pci/controller/pcie-mediatek-gen3.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c > index f7048ea4c020..dccdfce12b1c 100644 > --- a/drivers/pci/controller/pcie-mediatek-gen3.c > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c > @@ -838,6 +838,14 @@ static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie) > if (err) > return err; > > + /* > + * The controller may have been left out of reset by the bootloader > + * so make sure that we get a clean start by asserting resets here. > + */ > + reset_control_assert(pcie->phy_reset); > + reset_control_assert(pcie->mac_reset); > + usleep_range(10, 20); > + > /* Don't touch the hardware registers before power up */ > err = mtk_pcie_power_up(pcie); > if (err)