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Commit 5fe5db05 authored by Sheng Yang's avatar Sheng Yang Committed by Jesse Barnes
Browse files

PCI: Speed up device reset function 



For all devices need to do function level reset, currently we need wait for
at least 200ms, which can be too long if we have lots of devices...

The patch checked pending bit before msleep() to skip some unnecessary
sleeping interval.

Signed-off-by: default avatarSheng Yang <sheng@linux.intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 4c9c1686

drivers/pci/pci.c

+29 −17
Original line number Diff line number Diff line
@@ -2028,9 +2028,15 @@ static int __pcie_flr(struct pci_dev *dev, int probe) 
	pci_block_user_cfg_access(dev);



	/* Wait for Transaction Pending bit clean */

	pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status);

	if (!(status & PCI_EXP_DEVSTA_TRPND))

		goto transaction_done;



	msleep(100);

	pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status);

	if (status & PCI_EXP_DEVSTA_TRPND) {

	if (!(status & PCI_EXP_DEVSTA_TRPND))

		goto transaction_done;



	dev_info(&dev->dev, "Busy after 100ms while trying to reset; "

			"sleeping for 1 second\n");

	ssleep(1);
@@ -2038,8 +2044,8 @@ static int __pcie_flr(struct pci_dev *dev, int probe) 
	if (status & PCI_EXP_DEVSTA_TRPND)

		dev_info(&dev->dev, "Still busy after 1s; "

				"proceeding with reset anyway\n");

	}



transaction_done:

	pci_write_config_word(dev, exppos + PCI_EXP_DEVCTL,

				PCI_EXP_DEVCTL_BCR_FLR);

	mdelay(100);
@@ -2066,18 +2072,24 @@ static int __pci_af_flr(struct pci_dev *dev, int probe) 
	pci_block_user_cfg_access(dev);



	/* Wait for Transaction Pending bit clean */

	pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);

	if (!(status & PCI_AF_STATUS_TP))

		goto transaction_done;



	msleep(100);

	pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);

	if (status & PCI_AF_STATUS_TP) {

	if (!(status & PCI_AF_STATUS_TP))

		goto transaction_done;



	dev_info(&dev->dev, "Busy after 100ms while trying to"

			" reset; sleeping for 1 second\n");

	ssleep(1);

		pci_read_config_byte(dev,

				cappos + PCI_AF_STATUS, &status);

	pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);

	if (status & PCI_AF_STATUS_TP)

		dev_info(&dev->dev, "Still busy after 1s; "

				"proceeding with reset anyway\n");

	}



transaction_done:

	pci_write_config_byte(dev, cappos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);

	mdelay(100);