Message-ID: <9e8b957da24d7b1f532ed83ffb86ca37@mail.gmail.com>
Date:	Thu, 28 May 2015 19:05:35 +0530
From:	Kashyap Desai <kashyap.desai@...gotech.com>
To:	Bjorn Helgaas <bhelgaas@...gle.com>,
	"Robin H. Johnson" <robbat2@...too.org>
Cc:	Adam Radford <aradford@...il.com>,
	Neela Syam Kolli <megaraidlinux@....com>,
	linux-scsi@...r.kernel.org, arkadiusz.bubala@...n-e.com,
	Matthew Garrett <matthew.garrett@...ula.com>,
	Sumit Saxena <sumit.saxena@...gotech.com>,
	Uday Lingala <uday.lingala@...gotech.com>,
	"PDL,MEGARAIDLINUX" <megaraidlinux.pdl@...gotech.com>,
	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jean Delvare <jdelvare@...e.de>,
	Myron Stowe <myron.stowe@...hat.com>
Subject: RE: megaraid_sas: "FW in FAULT state!!", how to get more debug
 output? [BKO63661]

Bjorn/Robin,

Apologies for delay. Here is one quick suggestion as we have seen similar
issue (not exactly similar, but high probably to have same issue) while
controller is configured on VM as pass-through and VM reboot abruptly.
In that particular issue, driver interact with FW which may  require chip
reset to bring controller to operation state.

Relevant patch was submitted for only Older controller as it was only seen
for few MegaRaid controller. Below patch already try to do chip reset, but
only for limited controllers...I have attached one more patch which does
chip reset from driver load time for Thunderbolt/Invader/Fury etc. (In
your case you have Thunderbolt controller, so attached patch is required.)

http://www.spinics.net/lists/linux-scsi/msg67288.html

Please post the result with attached patch.

Thanks, Kashyap

> -----Original Message-----
> From: Bjorn Helgaas [mailto:bhelgaas@...gle.com]
> Sent: Thursday, May 28, 2015 5:55 PM
> To: Robin H. Johnson
> Cc: Adam Radford; Neela Syam Kolli; linux-scsi@...r.kernel.org;
> arkadiusz.bubala@...n-e.com; Matthew Garrett; Kashyap Desai; Sumit
Saxena;
> Uday Lingala; megaraidlinux.pdl@...gotech.com;
linux-pci@...r.kernel.org;
> linux-kernel@...r.kernel.org; Jean Delvare; Myron Stowe
> Subject: Re: megaraid_sas: "FW in FAULT state!!", how to get more debug
> output? [BKO63661]
>
> [+cc Jean, Myron]
>
> Hello megaraid maintainers,
>
> Have you been able to take a look at this at all?  People have been
reporting this
> issue since 2012 on upstream, Debian, and Ubuntu, and now we're getting
> reports on SLES.
>
> My theory is that the Linux driver relies on some MegaRAID
initialization done by
> the option ROM, and the bug happens when the BIOS doesn't execute the
option
> ROM.
>
> If that's correct, you should be able to reproduce it on any system by
booting
> Linux (v3.3 or later) without running the MegaRAID SAS 2208 option ROM
(either
> by enabling a BIOS "fast boot" switch, or modifying the BIOS to skip
it).  If the
> Linux driver doesn't rely on the option ROM, you might even be able to
> reproduce it by physically removing the option ROM from the MegaRAID.
>
> Bjorn
>
> On Wed, Apr 29, 2015 at 12:28:32PM -0500, Bjorn Helgaas wrote:
> > [+cc linux-pci, linux-kernel, Kashyap, Sumit, Uday, megaraidlinux.pdl]
> >
> > On Sun, Jul 13, 2014 at 01:35:51AM +0000, Robin H. Johnson wrote:
> > > On Sat, Jul 12, 2014 at 11:29:20AM -0600, Bjorn Helgaas wrote:
> > > > Thanks for the report, Robin.
> > > >
> > > > https://bugzilla.kernel.org/show_bug.cgi?id=63661 bisected the
> > > > problem to 3c076351c402 ("PCI: Rework ASPM disable code"), which
> > > > appeared in v3.3.  For starters, can you verify that, e.g., by
> > > > building
> > > > 69166fbf02c7 (the parent of 3c076351c402) to make sure that it
> > > > works, and building 3c076351c402 itself to make sure it fails?
> > > >
> > > > Assuming that's the case, please attach the complete dmesg and
> > > > "lspci -vvxxx" output for both kernels to the bugzilla.  ASPM is a
> > > > feature that is configured on both ends of a PCIe link, so I want
> > > > to see the lspci info for the whole system, not just the SAS
adapters.
> > > >
> > > > It's not practical to revert 3c076351c402 now, so I'd also like to
> > > > see the same information for the newest possible kernel (if this
> > > > is possible; I'm not clear on whether you can boot your system or
> > > > not) so we can figure out what needs to be changed.
> > > TL;DR: FastBoot is leaving the MegaRaidSAS in a weird state, and it
> > > fails to start; Commit 3c076351c402 did make it worse, but I think
> > > we're right that the bug lies in the SAS code.
> > >
> > > Ok, I have done more testing on it (40+ boots), and I think we can
> > > show the problem is somewhere in how the BIOS/EFI/ROM brings up the
> > > card in FastBoot more, or how it leaves the card.
> >
> > I attached your dmesg and lspci logs to
> > https://bugzilla.kernel.org/show_bug.cgi?id=63661, thank you!  You did
> > a huge amount of excellent testing and analysis, and I'm sorry that we
> > haven't made progress using the results.
> >
> > I still think this is a megaraid_sas driver bug, but I don't have
> > enough evidence to really point fingers.
> >
> > Based on your testing, before 3c076351c402 ("PCI: Rework ASPM disable
> > code"), megaraid_sas worked reliably.  After 3c076351c402,
> > megaraid_sas does not work reliably when BIOS Fast Boot is enabled.
> >
> > Fast Boot probably means we don't run the option ROM on the device.
> > Your dmesg logs show that in the working case, BIOS has enabled the
> > device.  In the failing case it has not.  They also show that when
> > Fast Boot is enabled, there's a little less MTRR write-protect space,
> > which I'm guessing is space that wasn't needed for shadowing option
> > ROMs.
> >
> > I suspect megaraid_sas depends on something done by the option ROM,
> > and that prior to 3c076351c402, Linux did something to ASPM that was
> > enough to make megaraid_sas work.
> >
> > I attached a couple debug patches to
> > https://bugzilla.kernel.org/show_bug.cgi?id=63661 that log all the
> > ASPM configuration the PCI core does.  One applies to 69166fbf02c7
> > (the pre-3c076351c402 commit), and the other applies to v4.1-rc1.
> > Could you boot both of those with "pci=earlydump" and attach the dmesg
> > logs to the bugzilla?  If you boot with the BIOS CMOS reset settings
> > (Fast Boot enabled and ASPM set to "BIOS"), I expect the 69166fbf02c7-
> > based kernel to work, and the v4.1-rc1-based one to fail.
> >
> > > Full boot of the system was difficult on the 3.2 kernels, they
> > > didn't make it to userspace for other stuff being too new. For
> > > testing, I compiled CONFIG_MEGARAID_SAS=y on 3.2, and =m on
> > > 3.16-rc4; that way when the initramfs & userspace failed, the
megaraid load
> was captured over IPMI serial.
> > >
> > > I've done a lot of the analysis below while capturing.
> > >
> > > I was going to be booting many times, so I flipped the 'Fast Boot'
> > > option back to Disabled, so I could more easily get to the BIOS
> > > settings to change options while testing. When I did so, an
> > > accidental boot on a kernel that previously failed suddenly worked,
> > > leading me to raise an eyebrow, and this expanded my test matrix
more.
> > >
> > > 3 kernels, 6 different BIOS config combinations (2x3) = 18 test
> > > cases Each configuration was booted at least twice; if the result of
> > > two boots was not identical, I booted a third time and took the
majority
> result.
> > >
> > > All kernels had no boot params involving PCI specified (none of
> > > pci=, pcie*=, disable_msi*).
> > >
> > > Kernels:
> > > K.1: Ubuntu's 3.16-rc4
> > > K.2: 3.2-rc4 3c076351c402 - aspm merged
> > > K.3: 3.2-rc4 69166fbf02c7 - aspm merge parent
> > > Notes: 3.2* compiled with GCC4.6, 3.16-rc4 with GCC4.8
> > >
> > > BIOS: Boot -> FastBoot:
> > > B1.1 Off
> > > B1.2 On (CMOS reset default)
> > >
> > > BIOS: Advanced -> PCIe/PCI/PnP Configuration -> ASPM Support
> > > B2.1 Force L0s
> > > B2.2 BIOS (CMOS reset default)
> > > B2.3 Disabled
> > >
> > > Reduced Kernaugh Map of results:
> > > Kernels,B1,B2:   Result
> > >   *, B1.1,    *  PASS
> > >   *, B1.2, B2.1  VARIABLE (9 runs: 5 fail, 4 pass, no kernel
> > > consistency) K.1, B1.2, B2.2  FAIL K.1, B1.2, B2.3  FAIL K.2, B1.2,
> > > B2.2  FAIL K.2, B1.2, B2.3  FAIL K.3, B1.2, B2.2  PASS K.3, B1.2,
> > > B2.3  PASS
> >
> > I'm not very practiced with Karnaugh maps, so correct me if my
> > understanding is wrong:
> >
> >   - Fast Boot disabled: all kernels always passed
> >
> >   - Fast Boot enabled, ASPM set to Force L0s enabled: variable; no
> >     consistency of results
> >
> >   - Fast Boot enabled, ASPM set to BIOS or Disabled: pre-3c076351c402
> >     always passed, post-3c076351c402 always failed
> >
> > Bjorn

Download attachment "fastboot_1.patch" of type "application/octet-stream" (6724 bytes)

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