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path: root/drivers/pci/probe.c
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Diffstat (limited to 'drivers/pci/probe.c')
-rw-r--r--drivers/pci/probe.c68
1 files changed, 31 insertions, 37 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6ab6bd3df4b..04e74f48571 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1363,31 +1363,25 @@ static int pcie_find_smpss(struct pci_dev *dev, void *data)
static void pcie_write_mps(struct pci_dev *dev, int mps)
{
- int rc, dev_mpss;
-
- dev_mpss = 128 << dev->pcie_mpss;
+ int rc;
if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
- if (dev->bus->self) {
- dev_dbg(&dev->bus->dev, "Bus MPSS %d\n",
- 128 << dev->bus->self->pcie_mpss);
+ mps = 128 << dev->pcie_mpss;
- /* For "MPS Force Max", the assumption is made that
+ if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT && dev->bus->self)
+ /* For "Performance", the assumption is made that
* downstream communication will never be larger than
* the MRRS. So, the MPS only needs to be configured
* for the upstream communication. This being the case,
* walk from the top down and set the MPS of the child
* to that of the parent bus.
+ *
+ * Configure the device MPS with the smaller of the
+ * device MPSS or the bridge MPS (which is assumed to be
+ * properly configured at this point to the largest
+ * allowable MPS based on its parent bus).
*/
- mps = 128 << dev->bus->self->pcie_mpss;
- if (mps > dev_mpss)
- dev_warn(&dev->dev, "MPS configured higher than"
- " maximum supported by the device. If"
- " a bus issue occurs, try running with"
- " pci=pcie_bus_safe.\n");
- }
-
- dev->pcie_mpss = ffs(mps) - 8;
+ mps = min(mps, pcie_get_mps(dev->bus->self));
}
rc = pcie_set_mps(dev, mps);
@@ -1395,25 +1389,22 @@ static void pcie_write_mps(struct pci_dev *dev, int mps)
dev_err(&dev->dev, "Failed attempting to set the MPS\n");
}
-static void pcie_write_mrrs(struct pci_dev *dev, int mps)
+static void pcie_write_mrrs(struct pci_dev *dev)
{
- int rc, mrrs, dev_mpss;
+ int rc, mrrs;
/* In the "safe" case, do not configure the MRRS. There appear to be
* issues with setting MRRS to 0 on a number of devices.
*/
-
if (pcie_bus_config != PCIE_BUS_PERFORMANCE)
return;
- dev_mpss = 128 << dev->pcie_mpss;
-
/* For Max performance, the MRRS must be set to the largest supported
* value. However, it cannot be configured larger than the MPS the
- * device or the bus can support. This assumes that the largest MRRS
- * available on the device cannot be smaller than the device MPSS.
+ * device or the bus can support. This should already be properly
+ * configured by a prior call to pcie_write_mps.
*/
- mrrs = min(mps, dev_mpss);
+ mrrs = pcie_get_mps(dev);
/* MRRS is a R/W register. Invalid values can be written, but a
* subsequent read will verify if the value is acceptable or not.
@@ -1421,38 +1412,41 @@ static void pcie_write_mrrs(struct pci_dev *dev, int mps)
* shrink the value until it is acceptable to the HW.
*/
while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
- dev_warn(&dev->dev, "Attempting to modify the PCI-E MRRS value"
- " to %d. If any issues are encountered, please try "
- "running with pci=pcie_bus_safe\n", mrrs);
rc = pcie_set_readrq(dev, mrrs);
- if (rc)
- dev_err(&dev->dev,
- "Failed attempting to set the MRRS\n");
+ if (!rc)
+ break;
+ dev_warn(&dev->dev, "Failed attempting to set the MRRS\n");
mrrs /= 2;
}
+
+ if (mrrs < 128)
+ dev_err(&dev->dev, "MRRS was unable to be configured with a "
+ "safe value. If problems are experienced, try running "
+ "with pci=pcie_bus_safe.\n");
}
static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
{
- int mps = 128 << *(u8 *)data;
+ int mps, orig_mps;
if (!pci_is_pcie(dev))
return 0;
- dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
- pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
+ mps = 128 << *(u8 *)data;
+ orig_mps = pcie_get_mps(dev);
pcie_write_mps(dev, mps);
- pcie_write_mrrs(dev, mps);
+ pcie_write_mrrs(dev);
- dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
- pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
+ dev_info(&dev->dev, "PCI-E Max Payload Size set to %4d/%4d (was %4d), "
+ "Max Read Rq %4d\n", pcie_get_mps(dev), 128 << dev->pcie_mpss,
+ orig_mps, pcie_get_readrq(dev));
return 0;
}
-/* pcie_bus_configure_mps requires that pci_walk_bus work in a top-down,
+/* pcie_bus_configure_settings requires that pci_walk_bus work in a top-down,
* parents then children fashion. If this changes, then this code will not
* work as designed.
*/