[PATCH 2/7] PCI: Separate pci_bus_read_dev_vendor_id from pci_scan_device

From: Yinghai Lu
Date: Sat Jan 21 2012 - 04:53:24 EST


Will reuse that function for pciehp probing.

-v2: according to Kenji, fix crs timeout checking, and export the function
for later using when pciehp is compiled as module.

Suggested-by: Matthew Wilcox <matthew@xxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/pci.h | 2 ++
drivers/pci/probe.c | 48 +++++++++++++++++++++++++++++++-----------------
2 files changed, 33 insertions(+), 17 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b74084e..8dadbd3 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -205,6 +205,8 @@ enum pci_bar_type {
pci_bar_mem64, /* A 64-bit memory BAR */
};

+bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl,
+ int crs_timeout);
extern int pci_setup_device(struct pci_dev *dev);
extern int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
struct resource *res, unsigned int reg);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 04e74f4..101e90f 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1113,40 +1113,54 @@ struct pci_dev *alloc_pci_dev(void)
}
EXPORT_SYMBOL(alloc_pci_dev);

-/*
- * Read the config data for a PCI device, sanity-check it
- * and fill in the dev structure...
- */
-static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
+bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
+ int crs_timeout)
{
- struct pci_dev *dev;
- u32 l;
int delay = 1;

- if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
- return NULL;
+ 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 NULL;
+ if (*l == 0xffffffff || *l == 0x00000000 ||
+ *l == 0x0000ffff || *l == 0xffff0000)
+ return false;

/* Configuration request Retry Status */
- while (l == 0xffff0001) {
+ while (*l == 0xffff0001) {
+ if (!crs_timeout)
+ return false;
+
msleep(delay);
delay *= 2;
- if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
- return NULL;
+ if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
+ return false;
/* Card hasn't responded in 60 seconds? Must be stuck. */
- if (delay > 60 * 1000) {
+ if (delay > crs_timeout) {
printk(KERN_WARNING "pci %04x:%02x:%02x.%d: not "
"responding\n", pci_domain_nr(bus),
bus->number, PCI_SLOT(devfn),
PCI_FUNC(devfn));
- return NULL;
+ return false;
}
}

+ return true;
+}
+EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);
+
+/*
+ * Read the config data for a PCI device, sanity-check it
+ * and fill in the dev structure...
+ */
+static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
+{
+ struct pci_dev *dev;
+ u32 l;
+
+ if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))
+ return NULL;
+
dev = alloc_pci_dev();
if (!dev)
return NULL;
--
1.7.7

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