From: Florian Fainelli <florian.fainelli@broadcom.com>
To: Bjorn Helgaas <helgaas@kernel.org>, Imre Kaloz <kaloz@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, Andreas Larsson <andreas@gaisler.com>,
sparclinux@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Shivasharan S <shivasharan.srikanteshwara@broadcom.com>,
Srinath Mannam <srinath.mannam@broadcom.com>,
Michael Chan <michael.chan@broadcom.com>,
Vikas Gupta <vikas.gupta@broadcom.com>
Subject: Re: [PATCH] PCI: Avoid D3 on PLX PEX 8532/8533/8548 downstream ports
Date: Mon, 12 Oct 2026 14:41:37 -0700 [thread overview]
Message-ID: <1e813008-1874-4164-a803-b1af26332d35@broadcom.com> (raw)
In-Reply-To: <20261012213447.GA1392402@bhelgaas>
On 10/12/26 14:34, Bjorn Helgaas wrote:
> [+cc several Broadcom folks, help with possible switch erratum]
>
> On Sun, Sep 27, 2026 at 12:56:09PM +0200, Imre Kaloz wrote:
>> Runtime PM suspends an idle downstream port of a PLX/Broadcom PEX
>> 8532/8533/8548 switch to D3hot, but that takes the whole switch down
>> with it: any device behind another port of the same switch then
>> faults with a fatal bus error on its next access, e.g. mptsas probe
>> on a Sun Ultra 45.
>>
>> This surfaced on sparc64 once commit a5fb3ff63287 ("PCI: Allow PCI
>> bridges to go to D3Hot on all non-x86") let bridges enter D3hot. Keep
>> these downstream ports out of D3 by setting PCI_DEV_FLAGS_NO_D3.
>
> I don't really have any objection to this, but I am concerned that
> this quirk only applies to a few specific devices, but
> https://admin.pci-ids.ucw.cz/read/PC/10b5 shows a TON of
> similar-looking switches that I assume have the same behavior, so
> this may be just the tip of the iceberg.
>
>> Fixes: a5fb3ff63287 ("PCI: Allow PCI bridges to go to D3Hot on all non-x86")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Imre Kaloz <kaloz@kernel.org>
Our internal portal does not have any document for the 8532/8533/8548 so
unfortunately I cannot help here with identifying an errata document.
--
Florian
next prev parent reply other threads:[~2026-10-12 21:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-27 10:56 Imre Kaloz
2026-10-12 17:00 ` Magnus Lindholm
2026-10-12 21:34 ` Bjorn Helgaas
2026-10-12 21:41 ` Florian Fainelli [this message]
2026-10-12 21:41 ` Bjorn Helgaas
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