Saturday, May 23, 2015, 3:53:37 AM, you wrote: > On 05/22/2015 04:11 AM, Sander Eikelenboom wrote: >> Hello Sander, >> >> Friday, May 15, 2015, 12:47:27 AM, you wrote: >> >>> Sorry for the resend, i messed up the to's en from's. >> >>> Hi Konrad / David, >> >>> One big snip on this thread, got some more debug info, hopefully this will >>> lead to something: >> >>> On a working kernel (with the two seemingly non related patches reverted) i >>> get: >> >>> [ 0.717796] pcifront pci-0: Allocated pdev @ 0xffff880019e11780 >>> pdev->sh_info @ 0xffff880018f58000 >>> [ 0.717848] pcifront pci-0: ?!?!? before alloc gntref: 0 >>> [ 0.717871] pcifront pci-0: ?!?!? after alloc gntref: 8 >>> [ 0.717892] pcifront pci-0: ?!?!? before alloc evtchn: -1 >>> [ 0.717915] pcifront pci-0: ?!?!? after alloc evtchn: 17 >>> [ 0.717984] pcifront pci-0: ?!?!? bound evtchn:17 to irqhandler:-1 err:31 >>> [ 0.721640] pcifront pci-0: publishing successful! >>> [ 0.723684] usbcore: registered new interface driver udlfb >>> [ 0.724664] xen:xen_evtchn: Event-channel device installed >>> [ 0.726597] pcifront pci-0: Installing PCI frontend >>> [ 0.726853] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled >>> [ 0.727059] pcifront pci-0: Creating PCI Frontend Bus 0000:00 >>> [ 0.727363] pcifront pci-0: PCI host bridge to bus 0000:00 >>> [ 0.727391] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] >>> [ 0.727417] pci_bus 0000:00: root bus resource [mem >>> 0x00000000-0xffffffffffff] >>> [ 0.727452] pci_bus 0000:00: root bus resource [bus 00-ff] >>> [ 0.727475] pci_bus 0000:00: scanning bus >>> [ 0.727503] pcifront pci-0: read dev=0000:00:00.0 - offset 0 size 4 >>> [ 0.728253] Linux agpgart interface v0.103 >>> [ 0.728387] Hangcheck: starting hangcheck timer 0.9.1 (tick is 180 >>> seconds, margin is 60 seconds). >>> [ 0.728474] [drm] Initialized drm 1.1.0 20060810 >>> [ 0.728551] [drm] radeon kernel modesetting enabled. >>> [ 0.730319] pcifront pci-0: ?!?!? pciback responded !!! irq:31 >>> irq_flags:ffff880019e100a8 ns: 1431641785551700000 ns_timeout: >>> 1431641787541235000 evtchn:17 gnt_ref:8 >>> [ 0.730319] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 0.730319] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 0.730319] pcifront pci-0: read got back value 11113f6 >>> [ 0.738845] pcifront pci-0: read dev=0000:00:00.0 - offset e size 1 >>> [ 0.744976] brd: module loaded >>> [ 0.745204] pcifront pci-0: ?!?!? pciback responded !!! irq:31 >>> irq_flags:ffff880019e100a8 ns: 1431641785562852000 ns_timeout: >>> 1431641787552580000 evtchn:17 gnt_ref:8 >>> [ 0.745204] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:14 size:1 >>> [ 0.745204] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:14 >>> size:1 >>> [ 0.745204] pcifront pci-0: read got back value 0 >>> [ 0.749204] pcifront pci-0: read dev=0000:00:00.0 - offset 6 size 2 >>> [ 0.750155] loop: module loaded >>> [ 0.752527] pcifront pci-0: ?!?!? pciback responded !!! irq:31 >>> irq_flags:ffff880019e100a8 ns: 1431641785570841000 ns_timeout: >>> 1431641787562917000 evtchn:17 gnt_ref:8 >>> [ 0.752527] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:6 size:2 >>> [ 0.752527] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:6 >>> size:2 >>> [ 0.752527] pcifront pci-0: read got back value 210 >>> [ 0.757187] pcifront pci-0: read dev=0000:00:00.0 - offset 34 size 1 >> >> >>> Were as in the non-working situation i get: >> >>> [ 0.751244] pcifront pci-0: Allocated pdev @ 0xffff880019ec2e00 >>> pdev->sh_info @ 0xffff88001aa51000 >>> [ 0.751295] pcifront pci-0: ?!?!? before alloc gntref: 0 >>> [ 0.751315] pcifront pci-0: ?!?!? after alloc gntref: 8 >>> [ 0.751334] pcifront pci-0: ?!?!? before alloc evtchn: -1 >>> [ 0.751355] pcifront pci-0: ?!?!? after alloc evtchn: 17 >>> [ 0.751422] pcifront pci-0: ?!?!? bound evtchn:17 to irqhandler:-1 err:31 >>> [ 0.755215] pcifront pci-0: publishing successful! >>> [ 0.757341] usbcore: registered new interface driver udlfb >>> [ 0.758365] xen:xen_evtchn: Event-channel device installed >>> [ 0.760419] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled >>> [ 0.760819] pcifront pci-0: Installing PCI frontend >>> [ 0.761518] pcifront pci-0: Creating PCI Frontend Bus 0000:00 >>> [ 0.761684] pcifront pci-0: PCI host bridge to bus 0000:00 >>> [ 0.761710] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] >>> [ 0.761733] pci_bus 0000:00: root bus resource [mem >>> 0x00000000-0xffffffffffff] >>> [ 0.761763] pci_bus 0000:00: root bus resource [bus 00-ff] >>> [ 0.761783] pci_bus 0000:00: scanning bus >>> [ 0.761805] pcifront pci-0: read dev=0000:00:00.0 - offset 0 size 4 >>> [ 0.767207] Linux agpgart interface v0.103 >>> [ 0.767362] Hangcheck: starting hangcheck timer 0.9.1 (tick is 180 >>> seconds, margin is 60 seconds). >>> [ 0.767439] [drm] Initialized drm 1.1.0 20060810 >>> [ 0.767515] [drm] radeon kernel modesetting enabled. >>> [ 0.766948] pcifront pci-0: pciback not responding!!! irq:31 >>> irq_flags:ffff880019ec0028 ns: 1431641983026498000 ns_timeout: >>> 1431641983026497000 evtchn:0 gnt_ref:0 >>> [ 0.766948] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 0.766948] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 0.766948] pcifront pci-0: other err read got back err: ffffffff value: >>> 0 >>> [ 2.762062] pcifront pci-0: read dev=0000:00:01.0 - offset 0 size 4 >>> [ 2.765203] pcifront pci-0: pciback not responding!!! irq:31 >>> irq_flags:ffff880019ec0028 ns: 1431641985026742000 ns_timeout: >>> 1431641985026741000 evtchn:0 gnt_ref:0 >>> [ 2.765203] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 2.765203] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 2.765203] pcifront pci-0: other err read got back err: ffffffff value: >>> 0 >>> [ 4.762172] pcifront pci-0: read dev=0000:00:02.0 - offset 0 size 4 >>> [ 4.764231] brd: module loaded >>> [ 4.765508] loop: module loaded >>> [ 4.766748] pcifront pci-0: pciback not responding!!! irq:31 >>> irq_flags:ffff880019ec0028 ns: 1431641987026850000 ns_timeout: >>> 1431641987026849000 evtchn:0 gnt_ref:0 >>> [ 4.766748] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 4.766748] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 4.766748] pcifront pci-0: other err read got back err: ffffffff value: >>> 0 >>> [ 6.762248] pcifront pci-0: read dev=0000:00:03.0 - offset 0 size 4 >>> [ 6.765545] pcifront pci-0: pciback not responding!!! irq:31 >>> irq_flags:ffff880019ec0028 ns: 1431641989026930000 ns_timeout: >>> 1431641989026929000 evtchn:0 gnt_ref:0 >>> [ 6.765545] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 6.765545] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 6.765545] pcifront pci-0: other err read got back err: ffffffff value: >>> 0 >>> [ 8.762329] pcifront pci-0: read dev=0000:00:04.0 - offset 0 size 4 >>> [ 8.765626] pcifront pci-0: pciback not responding!!! irq:31 >>> irq_flags:ffff880019ec0028 ns: 1431641991027006000 ns_timeout: >>> 1431641991027005000 evtchn:0 gnt_ref:0 >>> [ 8.765626] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 8.765626] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 8.765626] pcifront pci-0: other err read got back err: ffffffff value: >>> 0 >>> [ 10.762410] pcifront pci-0: read dev=0000:00:05.0 - offset 0 size 4 >>> [ 10.765701] pcifront pci-0: pciback not responding!!! irq:31 >>> irq_flags:ffff880019ec0028 ns: 1431641993027087000 ns_timeout: >>> 1431641993027086000 evtchn:0 gnt_ref:0 >>> [ 10.765701] pcifront pci-0: ?!?!? op cmd:0 err:0 info:0 offset:0 size:4 >>> [ 10.765701] pcifront pci-0: ?!?!? active_op cmd:0 err:0 info:0 offset:0 >>> size:4 >>> [ 10.765701] pcifront pci-0: other err read got back err: ffffffff value: >>> 0 >>> [ 12.762472] pcifront pci-0: read dev=0000:00:06.0 - offset 0 size 4 >> >> >>> So somehow in the non-working situation, pdev->evtchn and pdev->gnt_ref are >>> 0 in >>> xen-pcifront.c:do_pci_op(), so no wonder it's not getting a response back >>> ... >> >>> Question is .. why ? >> >>> -- >>> Sander >> >> >> Ping ? >> >> David / Boris, >> >> Any idea, since Konrad seems to be off for 2 weeks and we are at rc4 now. >>
> (+Rafael again) > So the immediate cause of those errors is that pdev->evtchn is 0. > Backend is not notified and things not go well then. > And it is indeed caused by 97badf873ab60e841243b66133ff9eff2a46ef29: > We allocate pcifront_sd in pcifront_scan_root() and then pass it to > pci_scan_bus_parented() as sysdata. Eventually this sysdata is used in > pcibios_root_bridge_prepare() as pci_sysdata. It is dereferenced as pci_sysdata->>companion (which I believe is aliased to pcifront_sd->pdev) > and then set_primary_fwnode() writes it, thus corrupting pcifront_sd->>pdev (and I think this is what sets evtchn to zero). > I don't have a fix for that. I will see what we can do on Tuesday since > I am out on Monday. So the bisection wasn't a red herring after all :-). Thanks for the fast analysis and moving this forward Boris, have a nice weekend ! -- Sander > Question to Rafael about commit 97badf873ab60e84124: is it really safe > to assume that bridge->bus->sysdata is a pointer to pci_sysdata in > pcibios_root_bridge_prepare()? It is declared as 'void *'. > -boris -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
