wcte12xp, wctdm24xxp: Add compile-time option to disable ASPM for PCIe devices.

Certain BIOSes appear to enable ASPM even though it is not fully supported by
the platform. Also, since the PCIe links for TDM cards are always in use it
does not make sense to allow them to transition to the disabled state.

Just turn off power management on the PCIe links completely. For more
information see http://lwn.net/Articles/449448/.

Internal-Issue-ID: DAHLIN-283
Signed-off-by: Shaun Ruffell <sruffell@digium.com>

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@10557 a0bf4364-ded3-4de4-8d8a-66a801d63aff

3 files changed, 33 insertions, 0 deletions

diff --git a/drivers/dahdi/voicebus/voicebus.h b/drivers/dahdi/voicebus/voicebus.h
index dd0809f..9518028 100644
--- a/drivers/dahdi/voicebus/voicebus.h
+++ b/drivers/dahdi/voicebus/voicebus.h
@@ -57,6 +57,15 @@
  * (and not tasklet). */
 #define CONFIG_VOICEBUS_INTERRUPT
 
+/*
+ * Enable the following definition in order to disable Active-State Power
+ * Management on the PCIe bridge for PCIe cards. This has been known to work
+ * around issues where the BIOS enables it on the cards even though the
+ * platform does not support it.
+ *
+ */
+#undef CONFIG_VOICEBUS_DISABLE_ASPM
+
 /* Define this to use a FIFO for the software echocan reference.
  * (experimental) */
 #undef CONFIG_VOICEBUS_ECREFERENCE
diff --git a/drivers/dahdi/wctdm24xxp/base.c b/drivers/dahdi/wctdm24xxp/base.c
index d324a2a..f7169d2 100644
--- a/drivers/dahdi/wctdm24xxp/base.c
+++ b/drivers/dahdi/wctdm24xxp/base.c
@@ -191,6 +191,11 @@ static const struct wctdm_desc wcaex410 = { "Wildcard AEX410", FLAG_EXPRESS, 4 }
 static const struct wctdm_desc wcha80000 = { "HA8-0000", 0, 8 };
 static const struct wctdm_desc wchb80000 = { "HB8-0000", FLAG_EXPRESS, 8 };
 
+static inline bool is_pcie(const struct wctdm *wc)
+{
+	return (wc->desc->flags & FLAG_EXPRESS) > 0;
+}
+
 /**
  * Returns true if the card is one of the Hybrid Digital Analog Cards.
  */
@@ -5679,6 +5684,13 @@ __wctdm_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	wc->vb.pdev = pdev;
 	wc->vb.debug = &debug;
 
+#ifdef CONFIG_VOICEBUS_DISABLE_ASPM
+	if (is_pcie(wc)) {
+		pci_disable_link_state(pdev->bus->self, PCIE_LINK_STATE_L0S |
+			PCIE_LINK_STATE_L1 | PCIE_LINK_STATE_CLKPM);
+	};
+#endif
+
 	if (is_hx8(wc)) {
 		wc->vb.ops = &hx8_voicebus_operations;
 		ret = voicebus_boot_init(&wc->vb, wc->board_name);
diff --git a/drivers/dahdi/wcte12xp/base.c b/drivers/dahdi/wcte12xp/base.c
index a2f341f..1495161 100644
--- a/drivers/dahdi/wcte12xp/base.c
+++ b/drivers/dahdi/wcte12xp/base.c
@@ -99,6 +99,11 @@ static const struct t1_desc te120p = {"Wildcard TE120P"};
 static const struct t1_desc te122 = {"Wildcard TE122"};
 static const struct t1_desc te121 = {"Wildcard TE121"};
 
+static inline bool is_pcie(const struct t1 *t1)
+{
+	return (0 == strcmp(t1->variety, te121.name));
+}
+
 /* names of HWEC modules */
 static const char *vpmadt032_name = "VPMADT032";
 static const char *vpmoct_name = "VPMOCT032";
@@ -2743,6 +2748,13 @@ static int __devinit te12xp_init_one(struct pci_dev *pdev, const struct pci_devi
 	}
 #endif /* CONFIG_VOICEBUS_ECREFERENCE */
 
+#ifdef CONFIG_VOICEBUS_DISABLE_ASPM
+	if (is_pcie(wc)) {
+		pci_disable_link_state(pdev->bus->self, PCIE_LINK_STATE_L0S |
+			PCIE_LINK_STATE_L1 | PCIE_LINK_STATE_CLKPM);
+	};
+#endif
+
 	snprintf(wc->name, sizeof(wc->name)-1, "wcte12xp%d", index);
 	pci_set_drvdata(pdev, wc);
 	wc->vb.ops = &voicebus_operations;