On Tue, Mar 19, 2013 at 9:46 AM, Chris Clayton <chris2553@xxxxxxxxxxxxxx> wrote: > Hi Bjorn, > > Sorry I meant to reply to your mail so that copy recipients will know the > outcome of the things you asked me to do. But then I forgot. Doh! You should > have received the attachment notification from bugzilla, I think. > > > On 03/15/13 22:48, Bjorn Helgaas wrote: >> >> On Tue, Mar 12, 2013 at 4:20 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >> wrote: >>> >>> On Sat, Mar 9, 2013 at 2:20 AM, Chris Clayton <chris2553@xxxxxxxxxxxxxx> >>> wrote: >>>> >>>> On 03/08/13 22:57, Bjorn Helgaas wrote: >> >> >>>>> Thanks. I opened this bug report: >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=54981 to keep track of >>>>> your logs. >> >> >> Hi Chris, >> >> The current Linux acpiphp driver doesn't do anything unless it finds >> devices with _EJ0 or _RMV methods, and your DSDT has neither. But I >> think that implementation is incorrect because I'm not convinced that >> those methods are required in order to do hotplug via ACPI. For >> example, your DSDT *does* have an _L01 method that does notifications >> to the root ports. I suspect that hotplug events on your box generate >> an SCI that invokes that method. Linux basically ignores the >> resulting notify events, and I suspect that hotplug works on Windows >> because it is paying attention to them. >> >> Can you build a kernel with CONFIG_ACPI_DEBUG=y, do the following, and >> attach all the output to the bugzilla? >> >> 1) Boot with empty ExpressCard slot (without using "pcie_ports=native") >> 2) # echo 0x00010004 > /sys/module/acpi/parameters/debug_layer >> 3) # echo 0x08000004 > /sys/module/acpi/parameters/debug_level >> 4) # lspci -vv >> 5) # setpci -s 1c.3 0x42.w >> 6) # setpci -s 1c.3 0x5a.w >> 7) # setpci -s 1c.3 0xd8.l >> 8) Insert ExpressCard >> 9) # setpci -s 1c.3 0x5a.w >> 10) # dmesg >> >> Here's what I think we'll see: >> >> - Slot Implemented (bit 8 of XCAP at 0x42) set, indicating a slot is >> implemented below this root port >> - Hot Plug SCI Enable (bit 30 of MPC at 0xd8) set, indicating that the >> root port should generate an SCI whenever a hotplug event is detected >> - Presence Detect State (bit 6 of SLTSTS at 0x5a) change from 0 with >> the slot empty to 1 with the slot occupied >> - pciehp doing nothing (since _OSC didn't grant the OS permission to >> use PCIe native hotplug) >> - dmesg indication of the SCI, leading to a Bus Check notification to >> \_SB.PCI0.RP04, which is the 1c.3 root port leading to the ExpressCard >> slot >> > > As far as I can see, your predicted outcomes where correct. I've added the > logs to the bugzilla report. Yes, it behaved exactly as I expected. I attached a few more details of the analysis to the bug report (https://bugzilla.kernel.org/show_bug.cgi?id=54981). I think we need to rework acpiphp to fix this. We will fix it, but I don't know who will do it, or when it will happen. My list is growing faster than I can deal with :( Thanks very much for your excellent data collection! Bjorn -- 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
