On Monday, April 16, 2012, Linus Torvalds wrote:
> On Mon, Apr 16, 2012 at 1:35 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> > From: Rafael J. Wysocki <rjw@xxxxxxx>
> >
> > Some shortcomings introduced into pci_restore_state() by commit
> > 26f41062f28d ("PCI: check for pci bar restore completion and
> > retry") have been fixed by recent commit ebfc5b802fa76 ("PCI: Fix
> > regression in pci_restore_state(), v3"), but that commit treats
> > all PCI devices as those with Type 0 configuration headers.
>
> Make me happier and just make all of this a helper function again.
> Call that helper function pci_restore_config_space(), and make the
> existing "pci_restore_config_space()" be called
> "pci_restore_config_space_range()" or something. Ok?
Something like this, you mean?
---
From: Rafael J. Wysocki <rjw@xxxxxxx>
Subject: PCI: Retry BARs restoration for Type 0 headers only
Some shortcomings introduced into pci_restore_state() by commit
26f41062f28d ("PCI: check for pci bar restore completion and
retry") have been fixed by recent commit ebfc5b802fa76 ("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 26f41062f28d for all header types except for Type 0.
Tested-by: Mikko Vinni <mmvinni@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/pci/pci.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
Index: linux/drivers/pci/pci.c
===================================================================
--- linux.orig/drivers/pci/pci.c
+++ linux/drivers/pci/pci.c
@@ -991,8 +991,8 @@ static void pci_restore_config_dword(str
}
}
-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(str
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 *d
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);
--
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