From 347277313768f026ee64bc0f9d085f89baf3a194 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Fri, 14 Oct 2011 14:56:15 -0500
Subject: [PATCH] --- yaml --- r: 270325 b: refs/heads/master c:
 a1c473aa11e61bc871be16279c9bf976acf22504 h: refs/heads/master i:   270323:
 fa7d50455e5f328650c163a16cde8944b031dc2e v: v3

---
 [refs]                  |  2 +-
 trunk/drivers/pci/pci.c | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 578b28e946ee..8f65fb641255 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 62f392ea5b5f87b641e16e61a4cedda21ef7341f
+refs/heads/master: a1c473aa11e61bc871be16279c9bf976acf22504
diff --git a/trunk/drivers/pci/pci.c b/trunk/drivers/pci/pci.c
index 7cd417e94058..6f45a73c6e9f 100644
--- a/trunk/drivers/pci/pci.c
+++ b/trunk/drivers/pci/pci.c
@@ -3202,8 +3202,6 @@ int pcie_set_readrq(struct pci_dev *dev, int rq)
 	if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
 		goto out;
 
-	v = (ffs(rq) - 8) << 12;
-
 	cap = pci_pcie_cap(dev);
 	if (!cap)
 		goto out;
@@ -3211,6 +3209,22 @@ int pcie_set_readrq(struct pci_dev *dev, int rq)
 	err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
 	if (err)
 		goto out;
+	/*
+	 * If using the "performance" PCIe config, we clamp the
+	 * read rq size to the max packet size to prevent the
+	 * host bridge generating requests larger than we can
+	 * cope with
+	 */
+	if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
+		int mps = pcie_get_mps(dev);
+
+		if (mps < 0)
+			return mps;
+		if (mps < rq)
+			rq = mps;
+	}
+
+	v = (ffs(rq) - 8) << 12;
 
 	if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) {
 		ctl &= ~PCI_EXP_DEVCTL_READRQ;