| Message ID | CAFJTrDsu4k80kLjF9yZzctjznbYJ74y4m-VT3Vkf3XtGQXGAMw@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Dear Matthew Minter, On Wed, 9 Jul 2014 18:08:07 +0100, Matthew Minter wrote: > This is something of a follow up to my previous thread: > Armada XP (mvebu) PCIe memory (BAR/window) re-allocation > > Thanks to the helpful patches provided to the mvebu PCIe subsystem, > hot-plug PCIe devices worked much better on this board, however I have > discovered one remaining issue regarding them, due to the fact the > legacy style IRQ is assigned during the fake "PCI BIOS" phase, devices > which are plugged after boot will not be given an IRQ and thus if they > do not support MSI/MSI-X will fail to initialize. > > This seems a fairly simple problem to squash and as such I have > written a small patch which helps solve this, however I am unsure if I > am doing this in a sensible way or if a different kind of rework is > needed here. Also, if this is the wrong mailing list to ask about this > please say so. > > Any comments regarding this patch or a better way to achieve this > would be greatly appreciated. Patch follows (sorry if the format is > off, still getting used to git format-patch). My knowledge of the PCI core is a bit too limited to judge whether this is the right solution or not. However, I would recommend you to send the patch and problem description to the linux-pci@vger.kernel.org mailing list, with Bjorn Helgaas <bhelgaas@google.com> in the recipients (he is the PCI subsystem maintainer). It would indeed be good if you could use git send-email, because your patch has been badly modified by your e-mail client :/ Best regards, Thomas
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 73aef51..eb4f93c 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/kernel.h> #include <linux/pci.h> +#include <linux/of_pci.h> #include <linux/errno.h> #include <linux/ioport.h> #include <linux/proc_fs.h> @@ -245,6 +246,16 @@ void pci_bus_add_device(struct pci_dev *dev) * are not assigned yet for some devices. */ pci_fixup_device(pci_fixup_final, dev); + /* + * Devices which are hot-added after boot have not + * been assigned an irq by the bios. + */ + if (unlikely(!dev->irq)) { + dev_dbg(&dev->dev, + "PCI device missing IRQ, attempting to assign one\n"); + pdev_fixup_irq(dev, pci_common_swizzle, + of_irq_parse_and_map_pci); + } pci_create_sysfs_dev_files(dev); pci_proc_attach_device(dev); diff --git a/drivers/pci/setup-irq.c b/drivers/pci/setup-irq.c index 4e2d595..38c96c8 100644 --- a/drivers/pci/setup-irq.c +++ b/drivers/pci/setup-irq.c @@ -22,7 +22,7 @@ void __weak pcibios_update_irq(struct pci_dev *dev, int irq) pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); } -static void pdev_fixup_irq(struct pci_dev *dev, +void pdev_fixup_irq(struct pci_dev *dev, u8 (*swizzle)(struct pci_dev *, u8 *), int (*map_irq)(const struct pci_dev *, u8, u8)) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 466bcd1..4c1b1b3 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1056,6 +1056,8 @@ void pci_assign_unassigned_bus_resources(struct pci_bus *bus); void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus); void pdev_enable_device(struct pci_dev *); int pci_enable_resources(struct pci_dev *, int mask); +void pdev_fixup_irq(struct pci_dev *, u8 (*)(struct pci_dev *, u8 *), + int (*)(const struct pci_dev *, u8, u8)); void pci_fixup_irqs(u8 (*)(struct pci_dev *, u8 *), int (*)(const struct pci_dev *, u8, u8));