From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH 2/2] PCI: armada8k: don't toggle reset twice Date: Thu, 10 Jan 2019 13:55:48 +0100 Message-ID: <20190110125548.GA29612@lunn.ch> References: <024cc24efa7b99186750f90c91880b29357d379d.1547123182.git.baruch@tkos.co.il> <94cd23a60c647020dd87a923684b59255b89f02c.1547123182.git.baruch@tkos.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <94cd23a60c647020dd87a923684b59255b89f02c.1547123182.git.baruch@tkos.co.il> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Baruch Siach Cc: linux-pwm@vger.kernel.org, Lorenzo Pieralisi , Sven Auhagen , Jason Cooper , linux-gpio@vger.kernel.org, linux-pci@vger.kernel.org, Linus Walleij , Bartosz Golaszewski , Thierry Reding , Thomas Petazzoni , Bjorn Helgaas , Gregory Clement , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth List-Id: linux-pwm@vger.kernel.org On Thu, Jan 10, 2019 at 02:26:22PM +0200, Baruch Siach wrote: > 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. Hi Baruch Is this double reset issue limited to just Mellanox NICs, or any device in the PCIe slot? This sounds more like a workaround than a fix. It would be good to investigate further and determine which end of the PCIe link has the problem. Thanks Andrew