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Commit 91295d79 authored by Sinan Kaya's avatar Sinan Kaya Committed by Bjorn Helgaas
Browse files

PCI: Handle FLR failure and allow other reset types 



pci_flr_wait() and pci_af_flr() functions assume graceful return even
though the device is inaccessible under error conditions.

Return -ENOTTY in error cases so that __pci_reset_function_locked() can
try other reset types if AF_FLR/FLR reset fails.

Signed-off-by: default avatarSinan Kaya <okaya@codeaurora.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent cb5e0d06

drivers/pci/pci.c

+10 −8
Original line number Diff line number Diff line
@@ -4017,7 +4017,7 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev) 
}

EXPORT_SYMBOL(pci_wait_for_pending_transaction);



static void pci_flr_wait(struct pci_dev *dev)

static int pci_flr_wait(struct pci_dev *dev)

{

	int delay = 1, timeout = 60000;

	u32 id;
@@ -4046,7 +4046,7 @@ static void pci_flr_wait(struct pci_dev *dev) 
		if (delay > timeout) {

			pci_warn(dev, "not ready %dms after FLR; giving up\n",

				 100 + delay - 1);

			return;

			return -ENOTTY;

		}



		if (delay > 1000)
@@ -4060,6 +4060,8 @@ static void pci_flr_wait(struct pci_dev *dev) 


	if (delay > 1000)

		pci_info(dev, "ready %dms after FLR\n", 100 + delay - 1);



	return 0;

}



/**
@@ -4088,13 +4090,13 @@ static bool pcie_has_flr(struct pci_dev *dev) 
 * device supports FLR before calling this function, e.g. by using the

 * pcie_has_flr() helper.

 */

void pcie_flr(struct pci_dev *dev)

int pcie_flr(struct pci_dev *dev)

{

	if (!pci_wait_for_pending_transaction(dev))

		pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");



	pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);

	pci_flr_wait(dev);

	return pci_flr_wait(dev);

}

EXPORT_SYMBOL_GPL(pcie_flr);
@@ -4127,8 +4129,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe) 
		pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");



	pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);

	pci_flr_wait(dev);

	return 0;

	return pci_flr_wait(dev);

}



/**
@@ -4379,8 +4380,9 @@ int __pci_reset_function_locked(struct pci_dev *dev) 
	if (rc != -ENOTTY)

		return rc;

	if (pcie_has_flr(dev)) {

		pcie_flr(dev);

		return 0;

		rc = pcie_flr(dev);

		if (rc != -ENOTTY)

			return rc;

	}

	rc = pci_af_flr(dev, 0);

	if (rc != -ENOTTY)

include/linux/pci.h

+1 −1
Original line number Diff line number Diff line
@@ -1082,7 +1082,7 @@ int pcie_get_mps(struct pci_dev *dev); 
int pcie_set_mps(struct pci_dev *dev, int mps);

int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,

			  enum pcie_link_width *width);

void pcie_flr(struct pci_dev *dev);

int pcie_flr(struct pci_dev *dev);

int __pci_reset_function_locked(struct pci_dev *dev);

int pci_reset_function(struct pci_dev *dev);

int pci_reset_function_locked(struct pci_dev *dev);