From 5a03d0c931980cd2993c33d445c1bc28126f6481 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Tue, 14 Oct 2014 08:06:15 +0000
Subject: [PATCH] bcm53xx: fix hangs in PCIe2 host driver
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Accessing CFG regs with no card present results in SoC hang.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
SVN-Revision: 42895
---
...2-bcma-add-new-PCIe2-driver-for-bcma.patch | 38 ++++++++++++++++---
1 file changed, 33 insertions(+), 5 deletions(-)
diff --git a/target/linux/bcm53xx/patches-3.14/170-pcie2-bcma-add-new-PCIe2-driver-for-bcma.patch b/target/linux/bcm53xx/patches-3.14/170-pcie2-bcma-add-new-PCIe2-driver-for-bcma.patch
index 11d4148ccd..84e6c06f5f 100644
--- a/target/linux/bcm53xx/patches-3.14/170-pcie2-bcma-add-new-PCIe2-driver-for-bcma.patch
+++ b/target/linux/bcm53xx/patches-3.14/170-pcie2-bcma-add-new-PCIe2-driver-for-bcma.patch
@@ -48,7 +48,7 @@ Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
+obj-$(CONFIG_PCI_BCMA) += pcie2-bcma.o
--- /dev/null
+++ b/drivers/pci/host/pcie2-bcma.c
-@@ -0,0 +1,591 @@
+@@ -0,0 +1,619 @@
+/*
+ * Northstar PCI-Express driver
+ * Only supports Root-Complex (RC) mode
@@ -113,6 +113,8 @@ Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
+#define BCM4352_D11AC2G_ID 0x43b2 /* 4352 802.11ac 2.4G device */
+#define BCM4352_D11AC5G_ID 0x43b3 /* 4352 802.11ac 5G device */
+
++static struct pci_ops bcma_pcie2_ops;
++
+static int bcma_pcie2_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
+{
+ struct pci_sys_data *sys = pdev->sysdata;
@@ -268,11 +270,26 @@ Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
+ * Check link status, return 0 if link is up in RC mode,
+ * otherwise return non-zero
+ */
-+static int bcma_pcie2_check_link(struct bcma_device *bdev, u32 allow_gen2)
++static int bcma_pcie2_check_link(struct bcma_device *bdev,
++ struct pci_sys_data *sys, u32 allow_gen2)
+{
+ u32 devfn = 0;
-+ u8 tmp8;
+ u32 tmp32;
++ u16 tmp16;
++ u8 tmp8;
++ int pos;
++ bool link = false;
++ /*
++ * Setup callback (bcma_pcie2_setup) is called in pcibios_init_hw before
++ * creating bus root, so we don't have it here yet. On the other hand
++ * we really want to use pci_bus_find_capability helper to check NLW.
++ * Let's fake simple pci_bus just to query for capabilities.
++ */
++ struct pci_bus bus = {
++ .number = 0,
++ .ops = &bcma_pcie2_ops,
++ .sysdata = sys,
++ };
+
+ tmp32 = bcma_pcie2_read_config32(bdev, 0, devfn, 0xdc);
+ tmp32 &= ~0xf;
@@ -292,7 +309,18 @@ Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
+ return -ENODEV;
+ }
+
-+ return 0;
++ /* NS PAX only changes NLW field when card is present */
++ pos = pci_bus_find_capability(&bus, devfn, PCI_CAP_ID_EXP);
++ if (pos) {
++ u8 nlw;
++
++ pci_bus_read_config_word(&bus, devfn, pos + PCI_EXP_LNKSTA,
++ &tmp16);
++ nlw = (tmp16 & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT;
++ link = (tmp16 & PCI_EXP_LNKSTA_DLLLA) || nlw != 0;
++ }
++
++ return link ? 0 : -ENODEV;
+}
+
+/*
@@ -559,7 +587,7 @@ Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
+ * Skip inactive ports -
+ * will need to change this for hot-plugging
+ */
-+ linkfail = bcma_pcie2_check_link(bdev, allow_gen2);
++ linkfail = bcma_pcie2_check_link(bdev, sys, allow_gen2);
+ if (linkfail)
+ break;
+
--
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