Re: [PATCH v2] PCI: Fix Intel i210 by avoiding overlapping of BARs

From: Michael Walle
Date: Thu Dec 23 2021 - 13:12:08 EST


Am 2021-12-23 17:37, schrieb Bjorn Helgaas:

I intended to change the quirk from FINAL to EARLY, but obviously
forgot. Here's the updated version:

commit bb5639b73a2d ("PCI: Work around Intel I210 ROM BAR overlap defect")
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Tue Dec 21 10:45:07 2021 -0600

PCI: Work around Intel I210 ROM BAR overlap defect

Per PCIe r5, sec 7.5.1.2.4, a device must not claim accesses to its
Expansion ROM unless both the Memory Space Enable and the Expansion ROM
Enable bit are set. But apparently some Intel I210 NICs don't work
correctly if the ROM BAR overlaps another BAR, even if the Expansion ROM is
disabled.

Michael reported that on a Kontron SMARC-sAL28 ARM64 system with U-Boot
v2021.01-rc3, the ROM BAR overlaps BAR 3, and networking doesn't work at
all:

BAR 0: 0x40000000 (32-bit, non-prefetchable) [size=1M]
BAR 3: 0x40200000 (32-bit, non-prefetchable) [size=16K]
ROM: 0x40200000 (disabled) [size=1M]

NETDEV WATCHDOG: enP2p1s0 (igb): transmit queue 0 timed out
Hardware name: Kontron SMARC-sAL28 (Single PHY) on SMARC Eval
2.0 carrier (DT)
igb 0002:01:00.0 enP2p1s0: Reset adapter

Previously, pci_std_update_resource() wrote the assigned ROM address to the
BAR only when the ROM was enabled. This meant that the I210 ROM BAR could
be left with an address assigned by firmware, which might overlap with
other BARs.

Quirk these I210 devices so pci_std_update_resource() always writes the
assigned address to the ROM BAR, whether or not the ROM is enabled.

Link: https://lore.kernel.org/r/20201230185317.30915-1-michael@xxxxxxxx
Link: https://bugzilla.kernel.org/show_bug.cgi?id=211105
Reported-by: Michael Walle <michael@xxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

Tested-by: Michael Walle <michael@xxxxxxxx>

Thanks,
-michael