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Subject[patch] pcie: utilize pcie transaction pending bit
From
Date
PCIE has a mechanism to wait for Non-Posted request to complete. I think
pci_disable_device is a good place to do this.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---
drivers/pci/pci.c | 21 +++++++++++++++++++++
include/linux/pci.h | 2 ++
2 files changed, 23 insertions(+)

Index: linux/drivers/pci/pci.c
===================================================================
--- linux.orig/drivers/pci/pci.c 2007-10-17 10:33:48.000000000 +0800
+++ linux/drivers/pci/pci.c 2007-10-22 14:22:53.000000000 +0800
@@ -314,6 +314,24 @@ int pci_find_ht_capability(struct pci_de
}
EXPORT_SYMBOL_GPL(pci_find_ht_capability);

+void pcie_wait_pending_transaction(struct pci_dev *dev)
+{
+ int pos;
+ u16 reg16;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
+ if (!pos)
+ return;
+ while (1) {
+ pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
+ if (!(reg16 & PCI_EXP_DEVSTA_TRPND))
+ break;
+ cpu_relax();
+ }
+
+}
+EXPORT_SYMBOL_GPL(pcie_wait_pending_transaction);
+
/**
* pci_find_parent_resource - return resource region of parent bus of given region
* @dev: PCI device structure contains resources to be searched
@@ -884,6 +902,9 @@ pci_disable_device(struct pci_dev *dev)
if (atomic_sub_return(1, &dev->enable_cnt) != 0)
return;

+ /* Wait for all transactions are finished before disabling the device */
+ pcie_wait_pending_transaction(dev);
+
pci_read_config_word(dev, PCI_COMMAND, &pci_command);
if (pci_command & PCI_COMMAND_MASTER) {
pci_command &= ~PCI_COMMAND_MASTER;
Index: linux/include/linux/pci.h
===================================================================
--- linux.orig/include/linux/pci.h 2007-10-17 10:33:52.000000000 +0800
+++ linux/include/linux/pci.h 2007-10-22 14:19:56.000000000 +0800
@@ -484,6 +484,7 @@ int pci_find_next_capability (struct pci
int pci_find_ext_capability (struct pci_dev *dev, int cap);
int pci_find_ht_capability (struct pci_dev *dev, int ht_cap);
int pci_find_next_ht_capability (struct pci_dev *dev, int pos, int ht_cap);
+void pcie_wait_pending_transaction(struct pci_dev *dev);
struct pci_bus *pci_find_next_bus(const struct pci_bus *from);

struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
@@ -749,6 +750,7 @@ static inline void pci_unregister_driver
static inline int pci_find_capability (struct pci_dev *dev, int cap) {return 0; }
static inline int pci_find_next_capability (struct pci_dev *dev, u8 post, int cap) { return 0; }
static inline int pci_find_ext_capability (struct pci_dev *dev, int cap) {return 0; }
+static inline void pcie_wait_pending_transaction(struct pci_dev *dev) {}
static inline const struct pci_device_id *pci_match_device(const struct pci_device_id *ids, const struct pci_dev *dev) { return NULL; }

/* Power management related routines */
-
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