From: "Pali Rohár" <pali@kernel.org>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: vtolkm@gmail.com, "Bjorn Helgaas" <helgaas@kernel.org>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
"Rob Herring" <robh@kernel.org>,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
"Marek Behún" <marek.behun@nic.cz>,
"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>
Subject: Re: PCI trouble on mvebu (Turris Omnia)
Date: Wed, 31 Mar 2021 18:15:42 +0200 [thread overview]
Message-ID: <20210331161542.3e57qdtwnoz74xea@pali> (raw)
In-Reply-To: <87im57pgjh.fsf@toke.dk>
On Wednesday 31 March 2021 16:02:42 Toke Høiland-Jørgensen wrote:
> Pali Rohár <pali@kernel.org> writes:
>
> > On Friday 26 March 2021 18:51:42 Toke Høiland-Jørgensen wrote:
> >> Pali Rohár <pali@kernel.org> writes:
> >> > On Friday 26 March 2021 17:54:38 Toke Høiland-Jørgensen wrote:
> >> >> So we have these
> >> >> cases:
> >> >>
> >> >> ASPM disabled: ath9k, ath10k and mt76 cards all work
> >> >> ASPM enabled, no patch: only mt76 card works
> >> >> ASPM enabled + patch: ath10k and mt76 cards work
> >> >>
> >> >> So IDK, maybe the ath9k card needs a quirk as well? Or the mvebu board
> >> >> is just generally flaky?
> >> >
> >> > I'm not sure. Maybe ASPM is somehow buggy on ath9k or needs some special
> >> > handling. But issue is not at PCI config space as ath9k driver start
> >> > initialization of this card. Needs also some debugging in ath9k driver
> >> > if it prints that strange "mac chip rev" error.
> >>
> >> Well that's just being output because it gets a revision that it doesn't
> >> recognise - which it seems to be just reading from a register:
> >>
> >> https://elixir.bootlin.com/linux/latest/source/drivers/net/wireless/ath/ath9k/hw.c#L255
> >>
> >> The value returned is consistent with the value returned just being
> >> 0xffffffff. Which from looking at ioread32() is the value being returned
> >> on a failed read. So there's a driver bug there - the check against -EIO
> >> here is obviously nonsensical:
> >>
> >> https://elixir.bootlin.com/linux/latest/source/drivers/net/wireless/ath/ath9k/hw.c#L290
> >>
> >> But the underlying cause appears to be that the read from the register
> >> fails, which I suppose is related to something the PCI bus does?
> >>
> >> > I think this issue should be handled separately. Could you report it
> >> > also to ath9k mailing list (and CC me)? Maybe other ath developers would
> >> > know some more details.
> >>
> >> I'll send a patch for the nonsensical check above, but other than that I
> >> think we're still in PCI land here, or?
> >
> > First, can you try to enable my quirk also for this ath9k card with ASPM
> > enabled?
>
> Yup, with this I get both devices working:
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 8ff690c7679d..7e2f9c69f6b2 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3583,6 +3583,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, quirk_no_bus_reset);
> * PCIe bridge has forced link speed to 2.5 GT/s via PCI_EXP_LNKCTL2 register.
> */
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset_and_no_retrain_link);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x002e, quirk_no_bus_reset_and_no_retrain_link);
>
> /*
> * Root port on some Cavium CN8xxx chips do not successfully complete a bus
Ok, thank you for testing!
I'm seeing that testing unit 0x0030 (AR93xx) also needs this quirk, so I
will mark all Atheros chips in above no bus reset list with no retrain
link quirk.
> >
> > I have there another ath9k card which after toggling link retraining
> > changes PCI device ID (really!) to 0xABCD. But lspci ...
> >
> > There is long story about broken ath9k cards that are reporting 0xABCD
> > id on x86 machines with specific BIOS versions. It can be find in
> > ath9k-devel mailing list archive:
> >
> > https://www.mail-archive.com/ath9k-devel@lists.ath9k.org/msg07529.html
> >
> > Maybe we now found root cause of this ABCD? If yes, then it also answers
> > why above ath9k driver check fails (device id was changed) and also
> > because kernel see correct id (kernel reads id before configuring ASPM
> > and therefore before triggering link retraining).
> >
> >> >> > Can you send PCI device id of your ath9k card (lspci -nn)? Because all
> >> >> > my tested ath9k cards have different PCI device id.
> >> >>
> >> >> [root@omnia-arch ~]# lspci -nn
> >> >> 00:01.0 PCI bridge [0604]: Marvell Technology Group Ltd. Device [11ab:6820] (rev 04)
> >> >> 00:02.0 PCI bridge [0604]: Marvell Technology Group Ltd. Device [11ab:6820] (rev 04)
> >> >> 00:03.0 PCI bridge [0604]: Marvell Technology Group Ltd. Device [11ab:6820] (rev 04)
> >> >> 01:00.0 Network controller [0280]: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) [168c:002e] (rev 01)
> >> >> 02:00.0 Network controller [0280]: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter [168c:003c]
> >> >
> >> > That is fine. Also all ath9k testing cards have id 0x002e.
> >
> > Today I found out that lspci -nn may lie! Please send output from
> > command: lspci -nn -x because real PCI device id can read only from -x
> > hexdump output.
>
> Without the quirk added to the ath9k:
>
> 01:00.0 Network controller [0280]: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) [168c:002e] (rev 01)
> 00: 8c 16 2e 00 02 00 10 00 01 00 80 02 10 00 00 00
> 10: 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 8c 16 a4 30
> 30: 00 00 00 00 40 00 00 00 00 00 00 00 3d 01 00 00
>
> 02:00.0 Network controller [0280]: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter [168c:003c]
> 00: 8c 16 3c 00 46 05 10 00 00 00 80 02 10 00 00 00
> 10: 04 00 20 e0 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 30: 00 00 20 ea 40 00 00 00 00 00 00 00 3e 01 00 00
>
> And with:
>
> 01:00.0 Network controller [0280]: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) [168c:002e] (rev 01)
> 00: 8c 16 2e 00 46 01 10 00 01 00 80 02 10 00 00 00
> 10: 04 00 00 e0 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 8c 16 a4 30
> 30: 00 00 00 00 40 00 00 00 00 00 00 00 3d 01 00 00
>
> 02:00.0 Network controller [0280]: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter [168c:003c]
> 00: 8c 16 3c 00 46 05 10 00 00 00 80 02 10 00 00 00
> 10: 04 00 20 e0 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 30: 00 00 20 ea 40 00 00 00 00 00 00 00 3e 01 00 00
>
Yesterday both MJ and Bjorn told me to use lspci '-b' switch which
instruct lspci to parse capabilities from config space (instead of
kernel cache).
Could you try to run 'lspci -nn -vv' and 'lspci -nn -vv -b' and compare
results? If something changes?
Anyway I have discussion with Adrian Chadd about 0xABCD issue and these
Qualcomm/Atheros cards. When post-AR9300 card is not initialized it
reports PCI device id 0xABCD. Pre-AR9300 cards should report correct PCI
device id even when it is not initialized. WLE200 is AR9287-based, so it
reports always correct id, should not change it during usage.
But seems that also this AR9287 has issue with EEPROM/OTP as you figured
out that ath9k driver is not able to read some device id from internal
register. So please prepare patch for fixing -EIO in ath9k.
PCI vendor & device id is in first 4 bytes and as you can see it is
correct and was not changed.
So I guess lspci output would not change for this card.
> Is that change in bytes 5 and 6 significant?
At offset 0x04 is 16bit PCI Command Register.
In second (with) output is set bit 2 which means that Bus Mastering is
enabled. This is normal and required when card communicate with system.
Then is enabled bit 6 (Parity Error Response) and bit 8 (SERR# Enable),
both for error reporting. This is normal when device is active.
So nothing suspicious here.
> -Toke
>
next prev parent reply other threads:[~2021-03-31 16:16 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-27 15:43 PCI trouble on mvebu (Turris Omnia) Toke Høiland-Jørgensen
2020-10-27 17:20 ` Bjorn Helgaas
2020-10-27 17:44 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-27 18:59 ` Toke Høiland-Jørgensen
2020-10-27 20:20 ` Toke Høiland-Jørgensen
2020-10-27 21:22 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-27 21:31 ` Toke Høiland-Jørgensen
2020-10-27 22:01 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-27 22:12 ` Toke Høiland-Jørgensen
2020-10-27 18:56 ` Toke Høiland-Jørgensen
2020-10-28 13:36 ` Toke Høiland-Jørgensen
2020-10-28 14:42 ` Bjorn Helgaas
2020-10-28 15:08 ` Toke Høiland-Jørgensen
2020-10-28 16:40 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-28 23:16 ` Bjorn Helgaas
2020-10-29 10:09 ` Pali Rohár
2020-10-29 10:56 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-29 11:12 ` Toke Høiland-Jørgensen
2020-10-29 19:30 ` Bjorn Helgaas
2020-10-29 19:56 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-29 19:57 ` Andrew Lunn
2020-10-29 21:55 ` Thomas Petazzoni
2020-10-29 20:18 ` Toke Høiland-Jørgensen
2020-10-29 22:09 ` Toke Høiland-Jørgensen
2020-10-29 20:58 ` Marek Behun
2020-10-30 10:08 ` Pali Rohár
2020-10-30 10:45 ` Marek Behun
2020-10-29 21:54 ` Thomas Petazzoni
2020-10-29 23:15 ` Toke Høiland-Jørgensen
2020-10-30 8:23 ` Thomas Petazzoni
2020-10-30 10:15 ` Pali Rohár
2020-10-29 10:41 ` Toke Høiland-Jørgensen
2020-10-29 11:18 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-30 11:23 ` Pali Rohár
2020-10-30 13:02 ` Toke Høiland-Jørgensen
2020-10-30 14:23 ` Pali Rohár
2020-10-30 14:54 ` ™֟☻̭҇ Ѽ ҉ ®
2020-10-31 12:49 ` Toke Høiland-Jørgensen
2020-11-02 15:24 ` Pali Rohár
2020-11-02 15:54 ` Toke Høiland-Jørgensen
2020-11-02 16:18 ` ™֟☻̭҇ Ѽ ҉ ®
2020-11-02 16:33 ` Toke Høiland-Jørgensen
2021-03-15 19:58 ` Pali Rohár
2021-03-16 9:25 ` Pali Rohár
2021-03-18 22:43 ` Toke Høiland-Jørgensen
2021-03-18 23:16 ` Pali Rohár
2021-03-26 12:50 ` Pali Rohár
2021-03-26 15:25 ` Toke Høiland-Jørgensen
2021-03-26 15:34 ` Pali Rohár
2021-03-26 16:54 ` Toke Høiland-Jørgensen
2021-03-26 17:11 ` Pali Rohár
2021-03-26 17:51 ` Toke Høiland-Jørgensen
2021-03-29 17:09 ` Pali Rohár
2021-03-31 14:02 ` Toke Høiland-Jørgensen
2021-03-31 16:15 ` Pali Rohár [this message]
2021-03-31 16:53 ` Toke Høiland-Jørgensen
2020-10-29 1:21 ` Marek Behun
2020-10-29 15:12 ` Rob Herring
2020-10-27 18:03 ` Marek Behun
2020-10-27 19:00 ` Toke Høiland-Jørgensen
2020-10-27 20:19 ` Marek Behun
2020-10-27 20:49 ` Toke Høiland-Jørgensen
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