Hi Bjorn, On 12/4/2015 4:06 PM, Bjorn Helgaas wrote: > I'm sitting on this for the moment because if you have _HPP, it seems > like that should be enough to get SERR# forwarding turned on, and if > it's not, I'd like to understand why. So no hurry, but I'm waiting on > your investigation. > > Bjorn Here is the overall summary after my investigation. It looks like the kernel covers the hotplug use case. This patch is needed for systems without hotplug support and when the firmware is not setting up the SERR. after boot /# dmesg | grep hpp [ 3.115227] pci 0004:01:00.0: program_hpp_type0:1376 [ 3.128870] pci 0004:01:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.149597] pci 0004:01:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 3.191601] pci 0004:02:08.0: program_hpp_type0:1376 [ 3.191611] pci 0004:02:08.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.206630] pci 0004:02:08.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 3.253760] pci 0004:03:00.0: program_hpp_type0:1376 [ 3.267335] pci 0004:03:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.288046] pci 0004:03:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 3.355296] pci 0004:04:00.0: program_hpp_type0:1376 [ 3.355306] pci 0004:04:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.370334] pci 0004:04:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR / # lspci 00:00.0 Class 0604: 17cb:0400 01:00.0 Class 0604: 10b5:8732 02:08.0 Class 0604: 10b5:8732 03:00.0 Class 0604: 10b5:8732 04:00.0 Class 0604: 10b5:8732 / # Without hpp in ACPI table, SERR is not enabled. /# dmesg | grep type0 /# Power up with HPP after boot. [ 3.129325]_pci_0004:01:00.0:_program_hpp_type0:1376 [ 3.143286] pci 0004:01:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.164016] pci 0004:01:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 3.206019] pci 0004:02:08.0: program_hpp_type0:1376 [ 3.206028] pci 0004:02:08.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.220609] pci 0004:02:08.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 3.267783] pci 0004:03:00.0: program_hpp_type0:1376 [ 3.281420] pci 0004:03:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.302197] pci 0004:03:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 3.369684] pci 0004:04:00.0: program_hpp_type0:1376 [ 3.369694] pci 0004:04:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 3.384080] pci 0004:04:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR hotplug eject hotplug insert [ 98.338131] pci 0004:01:00.0: program_hpp_type0:1376 [ 98.351813] pci 0004:01:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 98.373147] pci 0004:01:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 98.452051] pci 0004:02:08.0: program_hpp_type0:1376 [ 98.465772] pci 0004:02:08.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 98.487142] pci 0004:02:08.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 98.597579] pci 0004:03:00.0: program_hpp_type0:1376 [ 98.611290] pci 0004:03:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 98.632181] pci 0004:03:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR [ 98.736153] pci 0004:04:00.0: program_hpp_type0:1376 [ 98.750437] pci 0004:04:00.0: program_hpp_type0:1378 pci_cmd |= PCI_COMMAND_SERR [ 98.771202] pci 0004:04:00.0: program_hpp_type0:1391 pci_bctl |= PCI_BRIDGE_CTL_SERR / # -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
