On Tue, Sep 15, 2015 at 9:51 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > On 09/15/2015 09:30 AM, Lorenzo Pieralisi wrote: > > It looks like me and Yinghai disagree how the problem I was trying to fix > should be handled, I don't understand Yinghai's concerns, and unfortunately > I just don't have the time I would need to get a better understanding. > It is fine with me to revert your patch and abandon mine. I put one simplified version in one my branch. https://git.kernel.org/cgit/linux/kernel/git/yinghai/linux-yinghai.git/patch/?id=cdf4bfbc1ce12d826abd49a8987eb3ca7e129332 and will sent that later if needed. >From cdf4bfbc1ce12d826abd49a8987eb3ca7e129332 Mon Sep 17 00:00:00 2001 From: Guenter Roeck <linux@xxxxxxxxxxxx> Date: Tue, 15 Sep 2015 12:59:11 -0700 Subject: PCI: Only try to assign io port only for root bus that support it The PCI subsystem always assumes that I/O is supported on root bus and tries to assign an I/O window to each child bus even if that is not the case. This may result in messages such as: pcieport 0000:02:00.0: res[7]=[io 0x1000-0x0fff] get_res_add_size add_size 1000 pcieport 0000:02:00.0: BAR 7: no space for [io size 0x1000] pcieport 0000:02:00.0: BAR 7: failed to assign [io size 0x1000] for each bridge port, even if root does not support I/O in the first place. To avoid this message, check if root bus supports I/O, then child bus will inherit the setting from parent bus, and later during sizing and assigning, check that bus flags and skip those resources. [bhelgaas: reverse sense of new pci_bus_flags_t value] [yinghai: only check root bus io port, and use flag on sizing and assigning] Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> CC: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c4c6947..5d946bd 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -339,6 +339,9 @@ static void pci_read_bridge_io(struct pci_bus *child) struct pci_bus_region region; struct resource *res; + if (!(child->bus_flags & PCI_BUS_FLAGS_ROOT_SUPPORTS_IO)) + return; + io_mask = PCI_IO_RANGE_MASK; io_granularity = 0x1000; if (dev->io_window_1k) { @@ -2126,6 +2129,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, } else bus_addr[0] = '\0'; dev_info(&b->dev, "root bus resource %pR%s\n", res, bus_addr); + if (resource_type(res) == IORESOURCE_IO) + b->bus_flags |= PCI_BUS_FLAGS_ROOT_SUPPORTS_IO; } resource_list_for_each_entry(window, &bridge->windows) { diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 9d5e415..8ee5d17 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -223,6 +223,10 @@ static void pdev_assign_resources_prepare(struct pci_dev *dev, if (r->flags & IORESOURCE_PCI_FIXED) continue; + if ((r->flags & IORESOURCE_IO) && + !(dev->bus->bus_flags & PCI_BUS_FLAGS_ROOT_SUPPORTS_IO)) + continue; + if (resource_disabled(r) || r->parent) continue; @@ -1178,6 +1182,11 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, min_size = 0; } + if (!(bus->bus_flags & PCI_BUS_FLAGS_ROOT_SUPPORTS_IO)) { + b_res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED; + return; + } + min_align = window_alignment(bus, IORESOURCE_IO); list_for_each_entry(dev, &bus->devices, bus_list) { int i; diff --git a/include/linux/pci.h b/include/linux/pci.h index 5ed9bf1..790c534 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -193,6 +193,7 @@ typedef unsigned short __bitwise pci_bus_flags_t; enum pci_bus_flags { PCI_BUS_FLAGS_NO_MSI = (__force pci_bus_flags_t) 1, PCI_BUS_FLAGS_NO_MMRBC = (__force pci_bus_flags_t) 2, + PCI_BUS_FLAGS_ROOT_SUPPORTS_IO = (__force pci_bus_flags_t) 4, }; /* These values come from the PCI Express Spec */ -- cgit v0.10.2 -- 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
