On Thu, Sep 28, 2017 at 10:25:33AM +0100, Lorenzo Pieralisi wrote: > On Wed, Sep 27, 2017 at 02:55:02PM -0500, Bjorn Helgaas wrote: > > On Wed, Sep 27, 2017 at 11:30:34AM +0100, Lorenzo Pieralisi wrote: > > > On Wed, Sep 20, 2017 at 12:31:04PM +0100, Lorenzo Pieralisi wrote: > > > > On Tue, Sep 19, 2017 at 11:02:33AM -0700, Guenter Roeck wrote: > > > > > On Tue, Sep 19, 2017 at 10:12:32AM +0100, Lorenzo Pieralisi wrote: > > > > > > On Mon, Sep 18, 2017 at 07:00:55PM -0700, Guenter Roeck wrote: > > > > > > > I see the following runtime warnings in mainline when running alpha images in qemu. > > > > > > > > > > > > > > > > > > > > > Floppy drive(s): fd0 is 2.88M > > > > > > > ide0: disabled, no IRQ > > > > > > > ide0: failed to initialize IDE interface > > > > > > > ide0: disabling port > > > > > > > cmd64x 0000:00:02.0: IDE controller (0x1095:0x0646 rev 0x07) > > > > > > > CMD64x_IDE 0000:00:02.0: BAR 0: can't reserve [io 0x8050-0x8057] > > > > > > > cmd64x 0000:00:02.0: can't reserve resources > > > > > > > CMD64x_IDE: probe of 0000:00:02.0 failed with error -16 > > > > > > > ide_generic: please use "probe_mask=0x3f" module parameter for probing all legacy ISA IDE ports > > > > > > > ------------[ cut here ]------------ > > > > > > > WARNING: CPU: 0 PID: 1 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x94/0xd0 > > > > > > > sysfs: cannot create duplicate filename '/class/ide_port/ide0' > > > > > > > ... > > > > > > > > > > > > > > Trace: > > > > > > > [<fffffc00003308a0>] __warn+0x160/0x190 > > > > > > > [<fffffc000048c9f4>] sysfs_warn_dup+0x94/0xd0 > > > > > > > [<fffffc0000330928>] warn_slowpath_fmt+0x58/0x70 > > > > > > > [<fffffc000048c9f4>] sysfs_warn_dup+0x94/0xd0 > > > > > > > [<fffffc0000486d40>] kernfs_path_from_node+0x30/0x60 > > > > > > > [<fffffc00004874ac>] kernfs_put+0x16c/0x2c0 > > > > > > > [<fffffc00004874ac>] kernfs_put+0x16c/0x2c0 > > > > > > > [<fffffc000048d010>] sysfs_do_create_link_sd.isra.2+0x100/0x120 > > > > > > > [<fffffc00005b9d64>] device_add+0x2a4/0x7c0 > > > > > > > [<fffffc00005ba5cc>] device_create_groups_vargs+0x14c/0x170 > > > > > > > [<fffffc00005ba518>] device_create_groups_vargs+0x98/0x170 > > > > > > > [<fffffc00005ba690>] device_create+0x50/0x70 > > > > > > > [<fffffc00005df36c>] ide_host_register+0x48c/0xa00 > > > > > > > [<fffffc00005df330>] ide_host_register+0x450/0xa00 > > > > > > > [<fffffc00005ba2a0>] device_register+0x20/0x50 > > > > > > > [<fffffc00005df330>] ide_host_register+0x450/0xa00 > > > > > > > [<fffffc00005df944>] ide_host_add+0x64/0xe0 > > > > > > > [<fffffc000079b41c>] kobject_uevent_env+0x16c/0x710 > > > > > > > [<fffffc0000310288>] do_one_initcall+0x68/0x260 > > > > > > > [<fffffc00007b13bc>] kernel_init+0x1c/0x1a0 > > > > > > > [<fffffc00007b13a0>] kernel_init+0x0/0x1a0 > > > > > > > [<fffffc0000311868>] ret_from_kernel_thread+0x18/0x20 > > > > > > > [<fffffc00007b13a0>] kernel_init+0x0/0x1a0 > > > > > > > > > > > > > > ---[ end trace 24a70433c3e4d374 ]--- > > > > > > > ide0: disabling port > > > > > > > > > > > > > > [ multiple times ] > > > > > > > > > > > > > > A complete log is available at http://kerneltests.org/builders/qemu-alpha-master. > > > > > > > > > > > > > > Prior to the offending commit, the kernel log looks as follows. > > > > > > > > > > > > > > ... > > > > > > > Uniform Multi-Platform E-IDE driver > > > > > > > cmd64x 0000:00:02.0: IDE controller (0x1095:0x0646 rev 0x07) > > > > > > > cmd64x 0000:00:02.0: IDE port disabled > > > > > > > cmd64x 0000:00:02.0: 100% native mode on irq 28 > > > > > > > PCI: Setting latency timer of device 0000:00:02.0 to 64 > > > > > > > ide0: BM-DMA at 0x8040-0x8047 > > > > > > > Floppy drive(s): fd0 is 2.88M > > > > > > > ide0 at 0x8050-0x8057,0x8062 on irq 28 (serialized) > > > > > > > ide_generic: please use "probe_mask=0x3f" module parameter for probing all legacy ISA IDE ports > > > > > > > ide1 at 0x1f0-0x1f7,0x3f6 on irq 14 > > > > > > > ide2 at 0x170-0x177,0x376 on irq 15 > > > > > > > ide-gd driver 1.18 > > > > > > > ide-cd driver 5.00 > > > > > > > ... > > > > > > > > > > > > > > Reverting the commit is not possible due to context changes. > > > > > > > > > > > > > > Bisect log is attached. > > > > > > > > > > > > Ok thanks. Can you please check if the diff below fixes the issue ? > > > > > > > > > > > It does. Feel free to add > > > > > > > > > > Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > > > > > > > > > to the actual patch. > > > > > > > > > > > I think the problem is that now we allocate the IRQ at device_probe > > > > > > instead of device_add time, if the patch below fixes the issue the > > > > > > question is whether we want to move pci_assign_irq() to pci_device_add() > > > > > > for ALL PCI devices or just fix this for IDE subsytem. > > > > > > > > > > > > > > > > That I can not answer ... > > > > > > > > It is not a clean-cut answer. Moving pci_assign_irq() from > > > > > > > > pci_device_probe() > > > > > > > > to > > > > > > > > pci_device_add() > > > > > > > > would fix this issue too and just map/swizzle() irqs for ALL PCI devices > > > > earlier (even ones that are not even probed); it should have no side > > > > effects (famous last words) and would be a cleaner fix. > > > > Hmmm, this is ugly. I *think* this is related to ide_pci_init_two(). > > We already call pci_assign_irq() from pci_device_probe(), where we try > > to bind one device to a driver. But ide_pci_init_two() deals with > > *two* devices: the one pci_device_probe() is trying to bind, and > > another random one found via pci_get_slot(). We have not called > > pci_assign_irq() for this second device. > > > > That breaks the model the PCI core expects, where we call the driver > > probe method for device X, and that method deals only with device X. > > > > We can fix this by doing the pci_assign_irq() either in the PCI core's > > device add path or in the driver's probe path (ide_pci_init_two(), as > > in the patch below). Doing it in the PCI core is sort of ugly because > > there's no obvious reason why we should map/swizzle the IRQ if there's > > no driver. > > > > Doing it in the driver is also sort of ugly because this is something > > that should be confined to the core (pci_assign_irq() probably should > > be declared in drivers/pci/pci.h so it's not available outside the > > core). > > > > I think the patch below means we call pci_assign_irq() *twice* on the > > device we're binding: once from pci_device_probe() and again from > > do_ide_setup_pci_device(). And I guess we might call it twice for the > > second device, too: once from do_ide_setup_pci_device() and again if > > pci_device_probe() tries to bind it. It's probably idempotent, but it > > does seem a little ugly. > > > > I guess I agree that calling pci_assign_irq() from pci_device_add() is > > the lesser evil. That will do it unnecessarily in cases where a > > device doesn't have a driver, but it should be safe. It sets > > pdev->irq but probably doesn't touch the device itself. > > I will do that, actually this would reinstate the exact boot stage at > which pci_fixup_irqs() was called (except that pci_assign_irq() does > that on a per host-bridge basis and in core code) because > pci_fixup_irqs() was called after enumeration before PCI devices were > added (ie before calling pci_bus_add_devices()), it *should* be safe. > > > We do more IRQ setup at pci_enable_device()-time (or probe-time for > > arm64) via acpi_pci_irq_enable(). This also updates pdev->irq. I'd > > rather not do that part at device add-time, because it does things > > like allocate and enable interrupt links, and we shouldn't do that > > until we know we have a driver for the device. > > > > But this is potentially another problem for this "second-device" thing > > IDE does. We've called pci_assign_irq() but not acpi_pci_irq_enable() > > for the second device, so we may still get the wrong IRQ for it. > > I have not touched the ACPI irq assignment path with my patches on > purpose. Put it differently, PNP0A03 host bridges do not have any > {map/swizzle}_irq() hook (yet) so pci_assign_irq() does nothing on > them. ACPI based platforms never used pci_fixup_irqs() so I changed > nothing on them (and I doubt I can given how complicated x86 legacy > IRQ assignment code is in arch code). Right. This isn't a problem with your patches; it's just a problem with the ide_pci_init_two() strategy of looking at dev->irq for a device for which the core hasn't called the probe path. Bjorn
