From 6a802ef0af94e7148c3fef71f5502654b65ed46a Mon Sep 17 00:00:00 2001 From: Sinan Kaya Date: Tue, 29 Aug 2017 14:45:44 -0500 Subject: [PATCH] PCI: Factor out pci_bus_wait_crs() Configuration Request Retry Status (CRS) was previously hidden inside pci_bus_read_dev_vendor_id(). We want to add support for CRS in other situations, such as waiting for a device to become ready after a Function Level Reset. Move CRS handling into pci_bus_wait_crs() so it can be called from other places. Signed-off-by: Sinan Kaya [bhelgaas: pass pointer, not value, to pci_bus_wait_crs() so caller gets correct Vendor ID] Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 43 +++++++++++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 16 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 5e001bbc2392..f09d8cd3df7a 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1858,30 +1858,24 @@ static bool pci_bus_crs_vendor_id(u32 l) return (l & 0xffff) == 0x0001; } -bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, - int crs_timeout) +static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, + int timeout) { int delay = 1; - if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) - return false; + if (!pci_bus_crs_vendor_id(*l)) + return true; /* not a CRS completion */ - /* some broken boards return 0 or ~0 if a slot is empty: */ - if (*l == 0xffffffff || *l == 0x00000000 || - *l == 0x0000ffff || *l == 0xffff0000) - return false; + if (!timeout) + return false; /* CRS, but caller doesn't want to wait */ /* - * Configuration Request Retry Status. Some root ports return the - * actual device ID instead of the synthetic ID (0xFFFF) required - * by the PCIe spec. Ignore the device ID and only check for - * (vendor id == 1). + * We got the reserved Vendor ID that indicates a completion with + * Configuration Request Retry Status (CRS). Retry until we get a + * valid Vendor ID or we time out. */ while (pci_bus_crs_vendor_id(*l)) { - if (!crs_timeout) - return false; - - if (delay > crs_timeout) { + if (delay > timeout) { printk(KERN_WARNING "pci %04x:%02x:%02x.%d: not responding\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn)); @@ -1897,6 +1891,23 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, return true; } + +bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, + int timeout) +{ + if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) + return false; + + /* some broken boards return 0 or ~0 if a slot is empty: */ + if (*l == 0xffffffff || *l == 0x00000000 || + *l == 0x0000ffff || *l == 0xffff0000) + return false; + + if (pci_bus_crs_vendor_id(*l)) + return pci_bus_wait_crs(bus, devfn, l, timeout); + + return true; +} EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); /* -- 2.20.1