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Subject[PATCH v11 2/4] PCI: Factor out pci_bus_wait_crs()
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From: Sinan Kaya <okaya@codeaurora.org>

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: move CRS reserved Vendor ID test into pci_bus_wait_crs(), remove
EXPORT_SYMBOL]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 39 +++++++++++++++++++++++----------------
2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 22e061738c6f..b0857052c04a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -235,6 +235,7 @@ enum pci_bar_type {
pci_bar_mem64, /* A 64-bit memory BAR */
};

+bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, int timeout);
bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl,
int crs_timeout);
int pci_setup_device(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 08ea844ac4ba..342a86640c6b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1824,33 +1824,26 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
}
EXPORT_SYMBOL(pci_alloc_dev);

-bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
- int crs_timeout)
+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 ((*l & 0xffff) != 0x0001)
+ 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 ((*l & 0xffff) == 0x0001) {
- if (!crs_timeout)
- return false;
-
msleep(delay);
delay *= 2;

- 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));
@@ -1863,6 +1856,20 @@ 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;
+
+ return pci_bus_wait_crs(bus, devfn, l, timeout);
+}
EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);

/*
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