Re: Regression: 442ec4c04d1: PCI: dwc: all: Split struct pcie_port into host-only and core structures

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Peter Senna Tschudin <peter.senna@collabora.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	Jesper Nilsson <jesper.nilsson@axis.com>,
	Joao Pinto <Joao.Pinto@synopsys.com>,
	Richard Zhu <hongxing.zhu@nxp.com>,
	Gabriele Paoloni <gabriele.paoloni@huawei.com>,
	Jingoo Han <jingoohan1@gmail.com>,
	Pratyush Anand <pratyush.anand@gmail.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Stanimir Varbanov <svarbanov@mm-sol.com>,
	Minghuan Lian <minghuan.Lian@freescale.com>,
	Zhou Wang <wangzhou1@hisilicon.com>,
	Murali Karicheri <m-karicheri2@ti.com>,
	Niklas Cassel <niklas.cassel@axis.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Mingkai Hu <mingkai.hu@freescale.com>,
	Roy Zang <tie-fei.zang@freescale.com>,
	linux-arm-kernel@lists.infradead.org,
	Lucas Stach <l.stach@pengutronix.de>
Subject: Re: Regression: 442ec4c04d1: PCI: dwc: all: Split struct pcie_port into host-only and core structures
Date: Tue, 9 May 2017 17:27:01 +0100	[thread overview]
Message-ID: <20170509162701.GC24672@red-moon> (raw)
In-Reply-To: <20170508203325.GB9791@collabora.com>

On Mon, May 08, 2017 at 10:33:25PM +0200, Peter Senna Tschudin wrote:
> On Mon, May 08, 2017 at 06:55:36PM +0100, Lorenzo Pieralisi wrote:
> > On Mon, May 08, 2017 at 06:34:08PM +0200, Lucas Stach wrote:
> > > Am Montag, den 08.05.2017, 17:02 +0200 schrieb Peter Senna Tschudin:
> > > > Hello Kishon,
> > > > 
> > > > Our iMX6 hardware (imx6q-b850v3.dts) is not booting with latest
> > > > linux-next and I could bisect until:
> > > > 
> > > > commit 442ec4c04d1235f8c664a74004dae54a7a574d18
> > > > Author: Kishon Vijay Abraham I <kishon@ti.com>
> > > > Date:   Wed Feb 15 18:48:14 2017 +0530
> > > > 
> > > >     PCI: dwc: all: Split struct pcie_port into host-only and core structures
> > > > 
> > > > Which seem to be causing our issues. Our device (imx6q-b850v3.dts) boots
> > > > fine with 4.10, and also boots if we disable pcie with:
> > > 
> > > Are you sure about this bisect? It seems more likely that the secondary
> > > bus scanning goes wrong. It seems Lorenzo Pieralisi's cfg space
> > > non-posting patches landed in next, so the root cause of this might just
> > > be the driver hooking the wrong fault code now.
> > > 
> > > Async and synchronous aborts are different fault codes on ARM. Can you
> > > see of removing the "16 +" in hook_fault_code() in
> > > drivers/pci/dwc/pci-imx6.c fixes this issue?
> > 
> > You can also s/pci_remap_cfgspace/ioremap in pcie-designware-host.c
> > to see if my patches are the issue, it is quite a mechanical change.
> 
> No change. Exactly same issue, but I noticed that
> devm_pci_remap_cfgspace() is called twice for the same device, can this
> be a problem?

No and anyway, given that you basically tested with pci_remap_cfgspace()
reverted I do not see how it may affect your platform but that's not
what you are asking, so yes, it is safe to call it for multiple
resources in a given device, think of it as ioremap for configuration
space resources.

I still do not understand if you manage to bisect and fix the issue,
PCI tree was merged in the mainline last night so you could give it
a shot, it may be easier to bisect than -next.

Thanks !
Lorenzo

> ...
> [    0.505069] OF: PCI: host bridge /soc/pcie@1ffc000 ranges:
> [    0.510586] OF: PCI:    IO 0x01f80000..0x01f8ffff -> 0x00000000
> [    0.516474] OF: PCI:   MEM 0x01000000..0x01efffff -> 0x01000000
> [    0.522420] imx6q-pcie 1ffc000.pcie: devm_pci_remap_cfgspace()
> [    0.528656] imx6q-pcie 1ffc000.pcie: devm_pci_remap_cfgspace()
> ...

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