From shaohua.li@intel.com Fri Oct 26 22:23:37 2007 From: Shaohua Li Date: Wed, 24 Oct 2007 10:45:08 +0800 Subject: pcie: utilize pcie transaction pending bit To: linux-pci Cc: Greg KH Message-ID: <1193193908.27150.17.camel@sli10-conroe.sh.intel.com> 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 Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 21 +++++++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 23 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -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, ®16); + 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; --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -498,6 +498,7 @@ 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, @@ -759,6 +760,7 @@ 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) {} /* Power management related routines */ static inline int pci_save_state(struct pci_dev *dev) { return 0; }