1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index deb7fa9cc638..ea5e70486174 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3230,11 +3230,23 @@ void pci_reset_bridge_secondary_bus(struct pci_dev *dev)
         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
         ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
-        msleep(100);
+        /*
+         * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms.  Double
+         * this to 2ms to ensure that we meet the minium requirement.
+         */
+        msleep(2);
 
         ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
-        msleep(100);
+
+        /*
+         * Trhfa for conventional PCI is 2^25 clock cycles.
+         * Assuming a minimum 33MHz clock this results in a 1s
+         * delay before we can consider subordinate devices to
+         * be re-initialized.  PCIe has some ways to shorten this,
+         * but we don't make use of them yet.
+         */
+        ssleep(1);
 }
 EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus);