diff options
| author | Bill XIE <persmule@hardenedlinux.org> | 2022-08-04 21:52:05 +0800 |
|---|---|---|
| committer | Martin L Roth <gaumless@gmail.com> | 2022-08-07 19:49:35 +0000 |
| commit | 385e43274e515b1d235540323a4907514df765fd (patch) | |
| tree | aefd04ea29eeb02cf854d189a77343cea80f470f | |
| parent | 02f2b193840f68c41a91380be0dd4f435ab2f339 (diff) | |
pciexp_device: Handle unsupported requests in pciexp_get_ext_cap_offset()
Looking into pciexp_get_ext_cap_offset() it seems a little hackish
and prone to endless loops. Either it should limit the loop or bail
out when pci_read_config32() returns 0xffffffff, meaning "Unsupported
Requests".
This commit fixes an endless loop when the queried PCIe device is
downstream of a legacy PCI bus which doesn't support extended config
space, thus pci_read_config32() will return 0xffffffff, for example,
the combination below with CONFIG_PCIEXP_SUPPORT_RESIZABLE_BARS
enabled.
TEST=Build and boot to OS in ASUS P8C WS with the following
peripherals and CONFIG_PCIEXP_SUPPORT_RESIZABLE_BARS enabled:
00:1c.4 PCI bridge [0604]: Intel Corporation 7 Series/C210 Series
Chipset Family PCI Express Root Port 5 [8086:1e18] (rev c4)
00:1c.4/00.0 SATA controller [0106]: Marvell Technology Group Ltd.
88SE9170 PCIe 2.0 x1 2-port SATA 6 Gb/s Controller [1b4b:9170]
(rev 13)
00:1e.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge
[8086:244e] (rev a4)
00:1e.0/00.0 PCI bridge [0604]: PLX Technology, Inc. PEX 8111 PCI
Express-to-PCI Bridge [10b5:8111] (rev 21)
00:1e.0/03.0 FireWire (IEEE 1394) [0c00]: VIA Technologies, Inc.
VT6306/7/8 [Fire II(M)] IEEE 1394 OHCI Controller [1106:3044]
(rev c0)
00:1e.0/00.0/00.0 Network controller [0280]: Qualcomm Atheros AR93xx
Wireless Network Adapter [168c:0030] (rev 01)
with 00:1c.4/00.0 being successfully tuned with pciexp_tune_dev(), and
00: 1e.0/00.0/00.0 not tuned as expected.
Change-Id: Ibb92548c47288b40e851fcc0a8a37937e8bdbf3c
Signed-off-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66439
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
| -rw-r--r-- | src/device/pciexp_device.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/device/pciexp_device.c b/src/device/pciexp_device.c index c03c224003..ac4e668f08 100644 --- a/src/device/pciexp_device.c +++ b/src/device/pciexp_device.c @@ -15,6 +15,9 @@ static unsigned int pciexp_get_ext_cap_offset(const struct device *dev, unsigned unsigned int next_cap_offset, this_cap, cafe; do { this_cap = pci_read_config32(dev, this_cap_offset); + /* Bail out when this request is unsupported */ + if (this_cap == 0xffffffff) + break; cafe = pci_read_config32(dev, this_cap_offset + 4); if ((this_cap & 0xffff) == cap) { return this_cap_offset; |