[PATCH] PCI: xgene: Fix CRS SV comment
Bjorn Helgaas
helgaas at kernel.org
Tue Jan 26 16:35:03 EST 2021
From: Bjorn Helgaas <bhelgaas at google.com>
Configuration Request Retry Status ("CRS") must be supported by all PCIe
devices. CRS Software Visibility is an optional feature that enables a
Root Port to make CRS visible to software by returning a special data value
to complete a config read.
Clarify a comment to say that it is "CRS SV", not "CRS", that can be
enabled.
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
---
drivers/pci/controller/pci-xgene.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
index 85e7c98265e8..2afdc865253e 100644
--- a/drivers/pci/controller/pci-xgene.c
+++ b/drivers/pci/controller/pci-xgene.c
@@ -173,12 +173,13 @@ static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
/*
* The v1 controller has a bug in its Configuration Request
- * Retry Status (CRS) logic: when CRS is enabled and we read the
- * Vendor and Device ID of a non-existent device, the controller
- * fabricates return data of 0xFFFF0001 ("device exists but is not
- * ready") instead of 0xFFFFFFFF ("device does not exist"). This
- * causes the PCI core to retry the read until it times out.
- * Avoid this by not claiming to support CRS.
+ * Retry Status (CRS) logic: when CRS Software Visibility is
+ * enabled and we read the Vendor and Device ID of a non-existent
+ * device, the controller fabricates return data of 0xFFFF0001
+ * ("device exists but is not ready") instead of 0xFFFFFFFF
+ * ("device does not exist"). This causes the PCI core to retry
+ * the read until it times out. Avoid this by not claiming to
+ * support CRS SV.
*/
if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL))
--
2.25.1
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