Bjorn Helgaas <helgaas@xxxxxxxxxx> writes:
> Another experiment: build kernel without CONFIG_PCIEASPM, set $ROOT
> and $NIC appropriately, and try the following:
>
> # Set $ROOT and $NIC (update to match your system):
>
> # ROOT=00:02.0
> # NIC=02:00.0
(these matched the ath10k card, so just went with that)
> # Dump the Root Port and NIC Link registers:
>
> # setpci -s$ROOT CAP_EXP+0xc.l # Link Capabilities
> # setpci -s$ROOT CAP_EXP+0x10.w # Link Control
> # setpci -s$ROOT CAP_EXP+0x12.w # Link Status
# setpci -s$ROOT CAP_EXP+0xc.l
0003ac12
# setpci -s$ROOT CAP_EXP+0x10.w
0040
# setpci -s$ROOT CAP_EXP+0x12.w
1011
> # setpci -s$NIC CAP_EXP+0xc.l # Link Capabilities
> # setpci -s$NIC CAP_EXP+0x10.w # Link Control
> # setpci -s$NIC CAP_EXP+0x12.w # Link Status
# setpci -s$NIC CAP_EXP+0xc.l
00036c11
# setpci -s$NIC CAP_EXP+0x10.w
0000
# setpci -s$NIC CAP_EXP+0x12.w
1011
> # Retrain the link:
>
> # setpci -s$ROOT CAP_EXP+0x10.w=0x0020 # Link Control Retrain Link
> # sleep 1
> # setpci -s$ROOT CAP_EXP+0x12.w # Link Status
> # setpci -s$NIC CAP_EXP+0x12.w # Link Status
# setpci -s$ROOT CAP_EXP+0x10.w=0x0020
# sleep 1
# setpci -s$ROOT CAP_EXP+0x12.w
1011
# setpci -s$NIC CAP_EXP+0x12.w
setpci: 0000:02:00.0: Instance #0 of Capability 0010 not found - there are no capabilities with that id.
# setpci -s$ROOT CAP_EXP+0x10.w
0000
(nothing in the dmesg either) - rebooted before trying the below:
> # Set CommClk+ and retrain the link:
>
> # setpci -s$NIC CAP_EXP+0x10.w=0x0040 # Link Control Common Clock
> # setpci -s$ROOT CAP_EXP+0x10.w=0x0040 # Link Control Common Clock
> # setpci -s$ROOT CAP_EXP+0x10.w=0x0060 # Link Control RL + CC
> # sleep 1
> # setpci -s$ROOT CAP_EXP+0x12.w # Link Status
> # setpci -s$NIC CAP_EXP+0x12.w # Link Status
# setpci -s$NIC CAP_EXP+0x10.w=0x0040
# setpci -s$ROOT CAP_EXP+0x10.w=0x0040
# setpci -s$ROOT CAP_EXP+0x10.w=0x0060
# sleep 1
# setpci -s$ROOT CAP_EXP+0x12.w
1011
# setpci -s$NIC CAP_EXP+0x12.w
setpci: 0000:02:00.0: Instance #0 of Capability 0010 not found - there are no capabilities with that id.
# lspci -v
00:01.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04) (prog-if 00 [Normal decode])
Device tree node: /sys/firmware/devicetree/base/soc/pcie/pcie@1,0
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
I/O behind bridge: [disabled]
Memory behind bridge: e0000000-e00fffff [size=1M]
Prefetchable memory behind bridge: 00000000-000fffff [size=1M]
Expansion ROM at e0100000 [virtual] [disabled] [size=2K]
Capabilities: [40] Express Root Port (Slot+), MSI 00
lspci: Unable to load libkmod resources: error -12
00:02.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04) (prog-if 00 [Normal decode])
Device tree node: /sys/firmware/devicetree/base/soc/pcie/pcie@2,0
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
I/O behind bridge: [disabled]
Memory behind bridge: e0200000-e04fffff [size=3M]
Prefetchable memory behind bridge: 00000000-000fffff [size=1M]
Expansion ROM at e0500000 [virtual] [disabled] [size=2K]
Capabilities: [40] Express Root Port (Slot+), MSI 00
00:03.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04) (prog-if 00 [Normal decode])
Device tree node: /sys/firmware/devicetree/base/soc/pcie/pcie@3,0
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=03, subordinate=03, sec-latency=0
I/O behind bridge: [disabled]
Memory behind bridge: e0600000-e07fffff [size=2M]
Prefetchable memory behind bridge: 00000000-000fffff [size=1M]
Expansion ROM at e0800000 [virtual] [disabled] [size=2K]
Capabilities: [40] Express Root Port (Slot+), MSI 00
01:00.0 Network controller: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
Subsystem: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express)
Flags: bus master, fast devsel, latency 0, IRQ 60
Memory at e0000000 (64-bit, non-prefetchable) [size=64K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit-
Capabilities: [60] Express Legacy Endpoint, MSI 00
Capabilities: [100] Advanced Error Reporting
Capabilities: [140] Virtual Channel
Capabilities: [160] Device Serial Number 00-15-17-ff-ff-24-14-12
Capabilities: [170] Power Budgeting <?>
Kernel driver in use: ath9k
02:00.0 Network controller: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter (rev ff) (prog-if ff)
!!! Unknown header type 7f
Kernel driver in use: ath10k_pci
03:00.0 Network controller: MEDIATEK Corp. Device 7612
Subsystem: MEDIATEK Corp. Device 7612
Flags: bus master, fast devsel, latency 0, IRQ 63
Memory at e0600000 (64-bit, non-prefetchable) [size=1M]
Expansion ROM at e0700000 [disabled] [size=64K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 00
Capabilities: [100] Advanced Error Reporting
Capabilities: [148] Device Serial Number 00-00-00-00-00-00-00-00
Capabilities: [158] Latency Tolerance Reporting
Capabilities: [160] L1 PM Substates
Kernel driver in use: mt76x2e
-Toke
