Hi, I am seeking feedback on an issue with an ExpressCard/54 USB 3.0 adapter that uses the Renesas uPD72020x chipset on a Lenovo X220i laptop. After a recent discussion on the linux-usb mailing list, we came to the conclusion that this seems to be a PCI issue. (https://marc.info/?t=150565318600001&r=1&w=2) For kernels versions >=4.12.8 the xhci driver performs a PCI reset for Renesas cards using `pci_reset_function_locked` at boot time which causes the card to stop responding: <snip> Sep 22 04:54:13 trinity kernel: [ 3.386192] xhci_hcd 0000:05:00.0: xHCI host controller not responding, assume dead Sep 22 04:54:13 trinity kernel: [ 3.386281] xhci_hcd 0000:05:00.0: remove, state 1 Sep 22 04:54:13 trinity kernel: [ 3.386289] usb usb4: USB disconnect, device number 1 Sep 22 04:54:13 trinity kernel: [ 3.386536] xhci_hcd 0000:05:00.0: USB bus 4 deregistered Sep 22 04:54:13 trinity kernel: [ 3.387320] xhci_hcd 0000:05:00.0: remove, state 1 Sep 22 04:54:13 trinity kernel: [ 3.387327] usb usb3: USB disconnect, device number 1 Sep 22 04:54:13 trinity kernel: [ 3.390523] clocksource: Switched to clocksource tsc Sep 22 04:54:13 trinity kernel: [ 3.396867] xhci_hcd 0000:05:00.0: Host halt failed, -19 Sep 22 04:54:13 trinity kernel: [ 3.396921] xhci_hcd 0000:05:00.0: Host not accessible, reset failed. Sep 22 04:54:13 trinity kernel: [ 3.397289] xhci_hcd 0000:05:00.0: USB bus 3 deregistered </snip> The system becomes very sluggish with considerable mouse pointer delays that are followed by display driver errors such as - pipe A vblank wait timed out - pipe B vblank wait timed out after some minutes. In addition `/sys/bus/pci/slots/1/power` reports that the card is in standby mode rather than active and it also does not show up in the list of pci devices retrieved with `lspci`. Removing the card immediately resolves these issues. Please refer to https://weichselbraun.net/tmp/dmesg-4.13.3 https://weichselbraun.net/tmp/dmesg-pipe-a-vblank-timeout.log https://weichselbraun.net/tmp/dmesg-pipe-b-vblank-timeout.log for the full log messages. The same problem can also be reproduced with pre 4.12.8 kernels by hot plugging the card. Hot plugging does not yield any kernel messages but only a sluggish system. Again `/sys/bus/pci/slots/1/power` reports the card to be in standby mode. There are some indications that this problem might be related to the Lenovo laptop's power management: a) the card works out of the box with an HP Elitebook 8460p. b) disabling the PCI express power management in the Lenovo X220i's BIOS resolves the reported issue (the card work with all tested kernels (with/without PCI reset); even hot plugging works). c) with none-reset kernels (pre 4.12.8) it is possible to force a dysfunctional card (i.e., a card that has been removed and inserted again) to active mode by executing echo 1 > /sys/bus/pci/slots/1/power multiple times. Afterwards the card is fully operational. This is not possible with later kernel versions, since a PCI reset always leads to a dysfunctional card. Depending on whether this forced power-on works the kernel will log the following messages: - https://weichselbraun.net/tmp/force-power-failed.log - https://weichselbraun.net/tmp/force-power-succeeded.log Any help would be highly appreciated. I am willing to retrieve more information as well as to patch, compile and test possible fixes. Cheers, Albert :)
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