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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 <okaya@codeaurora.org>
[bhelgaas: pass pointer, not value, to pci_bus_wait_crs() so caller gets
correct Vendor ID]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Sinan Kaya 2017-08-29 14:45:44 -05:00 committed by Bjorn Helgaas
parent 62bc6a6f74
commit 6a802ef0af
1 changed files with 27 additions and 16 deletions
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43
drivers/pci/probe.c
View File

@ -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);
/*