This is a note to let you know that I've just added the patch titled
PCI: Fix pci_enable_acs() support for the ACS quirks
to the 6.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-fix-pci_enable_acs-support-for-the-acs-quirks.patch
and it can be found in the queue-6.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d1b7c32585eeaa670c1eadb79f8c9284214f7cab
Author: Jason Gunthorpe <jgg@xxxxxxxx>
Date: Wed Oct 16 20:52:33 2024 -0300
PCI: Fix pci_enable_acs() support for the ACS quirks
[ Upstream commit f3c3ccc4fe49dbc560b01d16bebd1b116c46c2b4 ]
There are ACS quirks that hijack the normal ACS processing and deliver to
to special quirk code. The enable path needs to call
pci_dev_specific_enable_acs() and then pci_dev_specific_acs_enabled() will
report the hidden ACS state controlled by the quirk.
The recent rework got this out of order and we should try to call
pci_dev_specific_enable_acs() regardless of any actual ACS support in the
device.
As before command line parameters that effect standard PCI ACS don't
interact with the quirk versions, including the new config_acs= option.
Link: https://lore.kernel.org/r/0-v1-f96b686c625b+124-pci_acs_quirk_fix_jgg@xxxxxxxxxx
Fixes: 47c8846a49ba ("PCI: Extend ACS configurability")
Reported-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/e89107da-ac99-4d3a-9527-a4df9986e120@xxxxxxxxxx
Closes: https://bugzilla.suse.com/show_bug.cgi?id=1229019
Tested-by: Steffen Dirkwinkel <me@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 85ced6958d6d1..51407c376a222 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1067,8 +1067,15 @@ static void pci_std_enable_acs(struct pci_dev *dev, struct pci_acs *caps)
static void pci_enable_acs(struct pci_dev *dev)
{
struct pci_acs caps;
+ bool enable_acs = false;
int pos;
+ /* If an iommu is present we start with kernel default caps */
+ if (pci_acs_enable) {
+ if (pci_dev_specific_enable_acs(dev))
+ enable_acs = true;
+ }
+
pos = dev->acs_cap;
if (!pos)
return;
@@ -1077,11 +1084,8 @@ static void pci_enable_acs(struct pci_dev *dev)
pci_read_config_word(dev, pos + PCI_ACS_CTRL, &caps.ctrl);
caps.fw_ctrl = caps.ctrl;
- /* If an iommu is present we start with kernel default caps */
- if (pci_acs_enable) {
- if (pci_dev_specific_enable_acs(dev))
- pci_std_enable_acs(dev, &caps);
- }
+ if (enable_acs)
+ pci_std_enable_acs(dev, &caps);
/*
* Always apply caps from the command line, even if there is no iommu.
