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Date:   Thu, 12 Dec 2019 00:52:55 +0000
From:   Andrew Murray <andrew.murray@arm.com>
To:     Robin Murphy <robin.murphy@arm.com>
Cc:     Vicente Bergas <vicencb@gmail.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Shawn Lin <shawn.lin@rock-chips.com>,
        Heiko Stuebner <heiko@sntech.de>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Frederick Lawler <fred@fredlawl.com>,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-rockchip@lists.infradead.org,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Stefan =?iso-8859-1?Q?M=E4tje?= <stefan.maetje@esd.eu>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [REGRESSION] PCI v5.5-rc1 breaks google kevin
Message-ID: <20191212005254.GE24359@e119886-lin.cambridge.arm.com>
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On Thu, Dec 12, 2019 at 12:12:56AM +0000, Robin Murphy wrote:
> Hi Vicente,
> 
> On 2019-12-11 11:38 pm, Vicente Bergas wrote:
> > Hi,
> > since v5.5-rc1 the google kevin chromebook does not boot.
> > Git bisect reports 5e0c21c75e8c PCI/ASPM: Remove pcie_aspm_enabled()
> > unnecessary locking
> > as the first bad commit.
> > 
> > In order to revert it from v5.5-rc1 i had to also revert some dependencies:
> > 5e0c21c75e8c08375a69710527e4a921b897cb7e
> > aff5d0552da4055da3faa27ee4252e48bb1f5821
> > 35efea32b26f9aacc99bf07e0d2cdfba2028b099
> > 687aaf386aeb551130f31705ce40d1341047a936
> > 72ea91afbfb08619696ccde610ee4d0d29cf4a1d
> > 87e90283c94c76ee11d379ab5a0973382bbd0baf
> > After reverting all of this, still no luck.
> > So, either the results of git bisect are not to be trusted, or
> > there are more bad commits.
> > 
> > By "does not boot" i mean that the display fails to start and
> > the display is the only output device, so debugging is quite difficult.
> 
> Assuming it's a manifestation of the same PCI breakage that Enric and
> Lorenzo figured out, there's a proposed fix here:
> https://lkml.org/lkml/2019/12/11/199

It's likely that any PCI driver that uses PCI IO with that controller will
suffer the same fate.

Vicente - can you try the patch that has been proposed and verify it fixes
the issue for you?

Thanks,

Andrew Murray

> 
> Robin.
> 
> > v5.5-rc1 as is (reverting no commits at all) works fine when disabling PCI:
> > # CONFIG_PCI is not set
> > 
> > Regards,
> >  ?Vicente.
> > 
> > 
> > _______________________________________________
> > Linux-rockchip mailing list
> > Linux-rockchip@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-rockchip