Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4348a2dc authored by Shaohua Li's avatar Shaohua Li Committed by Greg Kroah-Hartman
Browse files

pcie: utilize pcie transaction pending bit 



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: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 39ec4561

drivers/pci/pci.c

+21 −0
Original line number Diff line number Diff line
@@ -314,6 +314,24 @@ int pci_find_ht_capability(struct pci_dev *dev, int ht_cap) 
}

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;

include/linux/pci.h

+2 −0
Original line number Diff line number Diff line
@@ -498,6 +498,7 @@ int pci_find_next_capability (struct pci_dev *dev, u8 pos, int cap); 
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(struct pci_driver *drv) { } 
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; }