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PCI: Retry BARs restoration for Type 0 headers only

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Some shortcomings introduced into pci_restore_state() by commit
26f41062f2 ("PCI: check for pci bar restore completion and retry")
have been fixed by recent commit ebfc5b802f ("PCI: Fix regression in
pci_restore_state(), v3"), but that commit treats all PCI devices as
those with Type 0 configuration headers.

That is not entirely correct, because Type 1 and Type 2 headers have
different layouts.  In particular, the area occupied by BARs in Type 0
config headers contains the secondary status register in Type 1 ones and
it doesn't make sense to retry the restoration of that register even if
the value read back from it after a write is not the same as the written
one (it very well may be different).

For this reason, make pci_restore_state() only retry the restoration
of BARs for Type 0 config headers.  This effectively makes it behave
as before commit 26f41062f2 for all header types except for Type 0.

Tested-by: Mikko Vinni <mmvinni@yahoo.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Rafael J. Wysocki 2012-04-16 23:07:50 +02:00 committed by Linus Torvalds
parent 5191d566c0
commit a6cb9ee7ca
1 changed files with 15 additions and 9 deletions
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24
drivers/pci/pci.c
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@ -991,8 +991,8 @@ static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
}
}
static void pci_restore_config_space(struct pci_dev *pdev, int start, int end,
int retry)
static void pci_restore_config_space_range(struct pci_dev *pdev,
int start, int end, int retry)
{
int index;
@ -1002,6 +1002,18 @@ static void pci_restore_config_space(struct pci_dev *pdev, int start, int end,
retry);
}
static void pci_restore_config_space(struct pci_dev *pdev)
{
if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
pci_restore_config_space_range(pdev, 10, 15, 0);
/* Restore BARs before the command register. */
pci_restore_config_space_range(pdev, 4, 9, 10);
pci_restore_config_space_range(pdev, 0, 3, 0);
} else {
pci_restore_config_space_range(pdev, 0, 15, 0);
}
}
/**
* pci_restore_state - Restore the saved state of a PCI device
* @dev: - PCI device that we're dealing with
@ -1015,13 +1027,7 @@ void pci_restore_state(struct pci_dev *dev)
pci_restore_pcie_state(dev);
pci_restore_ats_state(dev);
pci_restore_config_space(dev, 10, 15, 0);
/*
* The Base Address register should be programmed before the command
* register(s)
*/
pci_restore_config_space(dev, 4, 9, 10);
pci_restore_config_space(dev, 0, 3, 0);
pci_restore_config_space(dev);
pci_restore_pcix_state(dev);
pci_restore_msi_state(dev);