diff mbox

PCI: Retry BARs restoration for Type 0 headers only

Message ID 201204162235.49901.rjw@sisk.pl
State Superseded, archived
Headers show

Commit Message

Rafael J. Wysocki April 16, 2012, 8:35 p.m. UTC 
From: Rafael J. Wysocki <rjw@sisk.pl>

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@yahoo.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/pci/pci.c |   18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

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Comments

Linus Torvalds April 16, 2012, 8:35 p.m. UTC | #1 
On Mon, Apr 16, 2012 at 1:35 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> 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?

                   Linus
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diff mbox

Patch

Index: linux/drivers/pci/pci.c
===================================================================
--- linux.orig/drivers/pci/pci.c
+++ linux/drivers/pci/pci.c
@@ -1015,13 +1015,17 @@  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);
+	if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
+		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);
+	} else {
+		pci_restore_config_space(dev, 0, 15, 0);
+	}
 
 	pci_restore_pcix_state(dev);
 	pci_restore_msi_state(dev);