[v5,14/14] PCI: Remove unused pcie_get_minimum_link()

Commit Message

Bjorn Helgaas March 30, 2018, 9:06 p.m. UTC

From: Bjorn Helgaas <[e-mail]>

In some cases pcie_get_minimum_link() returned misleading information
because it found the slowest link and the narrowest link without
considering the total bandwidth of the link.  For example, if the path
contained a 16 GT/s x1 link and a 2.5 GT/s x16 link,
pcie_get_minimum_link() returned 2.5 GT/s x1, which corresponds to 250 MB/s
of bandwidth, not the actual available bandwidth of about 2000 MB/s for a
16 GT/s x1 link.

Callers should use pcie_print_link_status() instead, or
pcie_bandwidth_available() if they need more detailed information.

Signed-off-by: Bjorn Helgaas <[e-mail]>
---
 drivers/pci/pci.c   |   43 -------------------------------------------
 include/linux/pci.h |    2 --
 2 files changed, 45 deletions(-)

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index cec7aed09f6b..b6951c44ae6c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5103,49 +5103,6 @@  int pcie_set_mps(struct pci_dev *dev, int mps)
 }
 EXPORT_SYMBOL(pcie_set_mps);
 
-/**
- * pcie_get_minimum_link - determine minimum link settings of a PCI device
- * @dev: PCI device to query
- * @speed: storage for minimum speed
- * @width: storage for minimum width
- *
- * This function will walk up the PCI device chain and determine the minimum
- * link width and speed of the device.
- */
-int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
-			  enum pcie_link_width *width)
-{
-	int ret;
-
-	*speed = PCI_SPEED_UNKNOWN;
-	*width = PCIE_LNK_WIDTH_UNKNOWN;
-
-	while (dev) {
-		u16 lnksta;
-		enum pci_bus_speed next_speed;
-		enum pcie_link_width next_width;
-
-		ret = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
-		if (ret)
-			return ret;
-
-		next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
-		next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
-			PCI_EXP_LNKSTA_NLW_SHIFT;
-
-		if (next_speed < *speed)
-			*speed = next_speed;
-
-		if (next_width < *width)
-			*width = next_width;
-
-		dev = dev->bus->self;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL(pcie_get_minimum_link);
-
 /**
  * pcie_bandwidth_available - determine minimum link settings of a PCIe
  *			      device and its bandwidth limitation
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 38f7957121ef..5ccee29fe1b1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1081,8 +1081,6 @@  int pcie_get_readrq(struct pci_dev *dev);
 int pcie_set_readrq(struct pci_dev *dev, int rq);
 int pcie_get_mps(struct pci_dev *dev);
 int pcie_set_mps(struct pci_dev *dev, int mps);
-int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
-			  enum pcie_link_width *width);
 u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 			     enum pci_bus_speed *speed,
 			     enum pcie_link_width *width);