From patchwork Thu Jan 10 12:26:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 10755683 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BBF6391E for ; Thu, 10 Jan 2019 12:28:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A93DD294A8 for ; Thu, 10 Jan 2019 12:28:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9BA4B295C4; Thu, 10 Jan 2019 12:28:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 22597294A8 for ; Thu, 10 Jan 2019 12:28:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=DcbuFZgX/JPJngNs6Ghxz7BgS6WvYtOUY4Q0/cqEh20=; b=So5xuHJ5xpfG5M dv37M1rC8KGAseAgcAeneK5vICMgsG1PWb/QooXPQX77Go+uOABOg5Pb70GSrysrT+KTWgsfV664k LrhHbQgl1PSb3AixUSOTGgYdMSxYm+Zm0R/iNF5wyetEcDqURQlXbW7vuGmssnU/c/OwV0OBBfzRt QLiRi0OVV9BX7AIonFA+pzUNqor+fs91mB/f545KjYqTv8XwwYu+kMVfr9gg6SWxC1ErKYPeVq7ca uKkwfpFDh//IifcneXz/G/z+i9qa8vuroKNgUhABICQU6WJyOb0x8X6Djvv0TE5a9k1Hq2ZuFg+4C q0GuSEc3LgQyFSEGjwgQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ghZRY-0005lI-70; Thu, 10 Jan 2019 12:28:16 +0000 Received: from guitar.tcltek.co.il ([192.115.133.116] helo=mx.tkos.co.il) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1ghZRJ-0005a2-Jg for linux-arm-kernel@lists.infradead.org; Thu, 10 Jan 2019 12:28:04 +0000 Received: from tarshish.tkos.co.il (unknown [10.0.8.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id 806E544087E; Thu, 10 Jan 2019 14:27:55 +0200 (IST) From: Baruch Siach To: Linus Walleij , Bartosz Golaszewski , Thierry Reding , Thomas Petazzoni , Lorenzo Pieralisi , Bjorn Helgaas Subject: [PATCH 2/2] PCI: armada8k: don't toggle reset twice Date: Thu, 10 Jan 2019 14:26:22 +0200 Message-Id: <94cd23a60c647020dd87a923684b59255b89f02c.1547123182.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.20.1 In-Reply-To: <024cc24efa7b99186750f90c91880b29357d379d.1547123182.git.baruch@tkos.co.il> References: <024cc24efa7b99186750f90c91880b29357d379d.1547123182.git.baruch@tkos.co.il> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190110_042801_941649_2A8CC2EF X-CRM114-Status: GOOD ( 16.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, Baruch Siach , Sven Auhagen , Jason Cooper , Andrew Lunn , linux-pci@vger.kernel.org, Gregory Clement , linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 3d71746c42 ("PCI: armada8k: Add support for gpio controlled reset signal") added reset signal support. Reset is unconditionally asserted and deasserted. Unfortunately, that commit breaks boot on Macchiatobin when a Mellanox NIC is in the PCIe slot. It turns out that you can toggle the reset signal only once. Another reset signal toggle makes access to PCI configuration registers stall indefinitely. U-Boot toggles the Macchiatobin PCIe reset line already at boot. Detect whether the bootloader changed the reset signal state using the get_direction operation. If direction is output don't touch the reset signal again. Otherwise, set direction to output and keep the reset asserted. Reported-by: Sven Auhagen Signed-off-by: Baruch Siach --- This patch depends on the mvebu get_direction implementation in the patch #1 of this series. Since get_direction implementation is not a pure fix it might be considered unfit for v5.0. In that case I'm OK with reverting 3d71746c42 in v5.0 to fix the Macchiatobin regression, and postpone this series to v5.1. --- drivers/pci/controller/dwc/pcie-armada8k.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-armada8k.c b/drivers/pci/controller/dwc/pcie-armada8k.c index b171b6bc15c8..132a86a1e1e7 100644 --- a/drivers/pci/controller/dwc/pcie-armada8k.c +++ b/drivers/pci/controller/dwc/pcie-armada8k.c @@ -257,12 +257,23 @@ static int armada8k_pcie_probe(struct platform_device *pdev) goto fail_clkreg; } - /* Get reset gpio signal and hold asserted (logically high) */ + /* Get reset gpio signal, don't change its setting */ pcie->reset_gpio = devm_gpiod_get_optional(dev, "reset", - GPIOD_OUT_HIGH); + GPIOD_ASIS); if (IS_ERR(pcie->reset_gpio)) { ret = PTR_ERR(pcie->reset_gpio); goto fail_clkreg; + } else if (pcie->reset_gpio && + gpiod_get_direction(pcie->reset_gpio) == 0) { + /* Reset signal is output. The bootloader has deasserted reset + * signal already. Don't do it again. + */ + dev_info(dev, "%s: leave reset signal unchanged\n", __func__); + devm_gpiod_put(dev, pcie->reset_gpio); + pcie->reset_gpio = NULL; + } else if (pcie->reset_gpio) { + /* Assert reset */ + gpiod_direction_output(pcie->reset_gpio, 1); } platform_set_drvdata(pdev, pcie);