From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f54.google.com ([209.85.220.54]:39946 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752920AbaIDUYn (ORCPT ); Thu, 4 Sep 2014 16:24:43 -0400 Received: by mail-pa0-f54.google.com with SMTP id fb1so20726097pad.27 for ; Thu, 04 Sep 2014 13:24:43 -0700 (PDT) Date: Thu, 4 Sep 2014 14:24:36 -0600 From: Bjorn Helgaas To: Lucas Stach Cc: linux-pci@vger.kernel.org, Richard Zhu , Shawn Guo Subject: Re: [PATCH 2/2] PCI: imx6: fix boot hang when link already enabled Message-ID: <20140904202436.GA17125@google.com> References: <1406830565-23450-1-git-send-email-l.stach@pengutronix.de> <1406830565-23450-3-git-send-email-l.stach@pengutronix.de> <20140814202248.GA2071@google.com> <1409743007.1535.1.camel@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1409743007.1535.1.camel@pengutronix.de> Sender: linux-pci-owner@vger.kernel.org List-ID: On Wed, Sep 03, 2014 at 01:16:47PM +0200, Lucas Stach wrote: > Am Donnerstag, den 14.08.2014, 14:22 -0600 schrieb Bjorn Helgaas: > > On Thu, Jul 31, 2014 at 08:16:05PM +0200, Lucas Stach wrote: > > > This fixes a boot hang observed when the bootloader > > > already enabled the PCIe link for it's own use. The > > > fundamental problem is that Freescale forgot to wire > > > up the core reset, so software doesn't have a sane way > > > to get the core into a defined state. > > > > > > According to the DW PCIe core reference manual configuration > > > of the core may only happen when the LTSSM is disabled, so > > > this is one of the first things we need to do. Apparently > > > this isn't safe to do when the LTSSM is in any other state > > > than "detect" as we observe an instant machine hang when > > > trying to do so while the link is already up. > > > > > > As a workaround force LTSSM into detect state right before > > > hitting the disable switch. > > > > Bjorn, > > I would have expected for this to show up in 3.17 as it fixes a real bug > and has been posted some time ago. While you have picked it up into your > pci/host-imx6 branch it doesn't show up in Linus tree nor in any pull > requests AFAICS. > Was it intentional from you to hold this patch or is this just an > oversight? Nope, I just missed it, thanks for the reminder. I put in my for-linus branch and will ask Linus to pull it after it's been in -next for a few days. Bjorn