Re: Add option to passively listen for PCIE hotplug events
From: Alan Jenkins
Date: Sun Nov 09 2008 - 11:06:31 EST
Alan Jenkins wrote:
Matthew Garrett wrote:
On Tue, Nov 04, 2008 at 03:44:23PM +0000, Alan Jenkins wrote:
I instrumented all the delays I could find. hpc_check_lnk_status() was
the only one that came up. 1000ms delay per call, and I get 6 such
delays.
Ok, which is getting called from pciehp_enable_slot(). I'm not quite
clear on why this is being called 6 times - any chance you can put a
dump_stack() in there? Some are probably directly from the resume
code. This confuses me a little, since there's a check for whether
there's a card in the slot first. If that fails, pciehp_enable_slot()
isn't called. If it succeeds, pciehp_enable_slot checks whether the
slot is already powered up. If it is, it bails before doing the link
setup.
Bump. In case you're still slightly confused, I've found out why. It
skips the slot power check because POWER_CTRL(ctrl) == 0. (See "Power
Controller" in the debug output below).
Interestingly, I can see that hpc_get_power_status() is still being
called from elsewhere. So I'm not sure why we avoid calling it here.
Should I try out the obvious dumb fix (removing the POWER_CTRL test)?
Ta
Alan
# modprobe pciehp pciehp_passive=1 pciehp_debug=1
dmesg output from last of 3 pcie slots:
[ 328.873347] pciehp 0000:00:1c.1:pcie02: hpc_check_lnk_status: lnk_status = 1011
[ 328.873347] pciehp 0000:00:1c.1:pcie02: Device 0000:03:00.0 already exists at 0000:03:00, cannot hot-add
[ 328.873347] pciehp 0000:00:1c.1:pcie02: Cannot add device at 0000:03:00
[ 328.873347] pciehp 0000:00:1c.1:pcie02: hpc_get_power_status: SLOTCTRL 58 value read 38
[ 328.873347] pciehp 0000:00:1c.1:pcie02: hpc_get_attention_status: SLOTCTRL 58, value read 38
[ 328.873347] pciehp 0000:00:1c.1:pcie02: service driver pciehp loaded
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Hotplug Controller:
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Seg/Bus/Dev/Func/IRQ : 0000:00:1c.2 IRQ 45
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Vendor ID : 0x8086
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Device ID : 0x2664
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Subsystem ID : 0x0000
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Subsystem Vendor ID : 0x0000
[ 328.873347] pciehp 0000:00:1c.2:pcie02: PCIe Cap offset : 0x40
[ 328.873347] pciehp 0000:00:1c.2:pcie02: PCI resource [8] : 0x3f00000@0xf8000000
[ 328.873347] pciehp 0000:00:1c.2:pcie02: PCI resource [9] : 0x7000000@0xf0000000
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Slot Capabilities : 0x00180560
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Physical Slot Number : 3
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Attention Button : no
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Power Controller : no
[ 328.873347] pciehp 0000:00:1c.2:pcie02: MRL Sensor : no
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Attention Indicator : no
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Power Indicator : no
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Hot-Plug Surprise : yes
[ 328.873347] pciehp 0000:00:1c.2:pcie02: EMI Present : no
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Command Completed : yes
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Slot Status : 0x0040
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Slot Control : 0x0000
[ 328.873347] pciehp 0000:00:1c.2:pcie02: HPC vendor_id 8086 device_id 2664 ss_vid 0 ss_did 0
[ 328.873347] pciehp 0000:00:1c.2:pcie02: Registering domain:bus:dev=0000:01:00 hp_slot=0 sun=3 slot_device_offset=0
[ 328.873347] pciehp 0000:00:1c.2:pcie02: get_power_status: physical_slot = 3
[ 328.873347] pciehp 0000:00:1c.2:pcie02: hpc_get_power_status: SLOTCTRL 58 value read 38
[ 328.873347] pciehp 0000:00:1c.2:pcie02: get_attention_status: physical_slot = 3
[ 328.873347] pciehp 0000:00:1c.2:pcie02: hpc_get_attention_status: SLOTCTRL 58, value read 38
[ 328.873347] pciehp 0000:00:1c.2:pcie02: get_latch_status: physical_slot = 3
[ 328.873347] pciehp 0000:00:1c.2:pcie02: get_adapter_status: physical_slot = 3
[ 328.873347] pciehp 0000:00:1c.2:pcie02: board_added: slot device, slot offset, hp slot = 0, 0, 0
[ 329.876677] pciehp 0000:00:1c.2:pcie02: hpc_check_lnk_status: DEBUG TIME 1000ms
[ 329.876677] Pid: 5101, comm: modprobe Not tainted 2.6.28-rc3eeepc #128
[ 329.876677] Call Trace:
[ 329.876677] [<e02d3b11>] hpc_check_lnk_status+0x107/0x1ba [pciehp]
[ 329.876677] [<e02d1eaa>] pciehp_enable_slot+0x19d/0x2c9 [pciehp]
[ 329.876677] [<e02d19b8>] pciehp_probe+0x3b2/0x3ee [pciehp]
[ 329.876677] [<c01c276d>] pcie_port_probe_service+0x29/0x63
[ 329.876677] [<c020759b>] driver_probe_device+0xa1/0x117
[ 329.876677] [<c020765a>] __driver_attach+0x49/0x67
[ 329.876677] [<c0206df8>] bus_for_each_dev+0x35/0x56
[ 329.876677] [<c020744a>] driver_attach+0x11/0x13
[ 329.876677] [<c0207611>] __driver_attach+0x0/0x67
[ 329.876677] [<c020713f>] bus_add_driver+0x91/0x192
[ 329.876677] [<c02077b1>] driver_register+0x6d/0xc2
[ 329.876677] [<c0191561>] sysfs_addrm_finish+0x13/0x16f
[ 329.876677] [<e027d000>] pcied_init+0x0/0x5c [pciehp]
[ 329.876677] [<e027d00b>] pcied_init+0xb/0x5c [pciehp]
[ 329.876677] [<c0101134>] _stext+0x4c/0x136
[ 329.876677] [<c01576c3>] __vunmap+0x7c/0x8a
[ 329.876677] [<c0135324>] load_module+0xfe3/0x10e8
[ 329.876677] [<e0046c77>] acpi_get_hp_params_from_firmware+0x0/0x49d [pci_hotplug]
[ 329.876677] [<c01354b0>] sys_init_module+0x87/0x177
[ 329.876677] [<c010376d>] sysenter_do_call+0x12/0x21
[ 329.876677] pciehp 0000:00:1c.2:pcie02: hpc_check_lnk_status: lnk_status = 1011
[ 329.876677] pciehp 0000:00:1c.2:pcie02: Device 0000:01:00.0 already exists at 0000:01:00, cannot hot-add
[ 329.876677] pciehp 0000:00:1c.2:pcie02: Cannot add device at 0000:01:00
[ 329.876677] pciehp 0000:00:1c.2:pcie02: hpc_get_power_status: SLOTCTRL 58 value read 38
[ 329.876677] pciehp 0000:00:1c.2:pcie02: hpc_get_attention_status: SLOTCTRL 58, value read 38
[ 329.876677] pciehp 0000:00:1c.2:pcie02: service driver pciehp loaded
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