[4.2.y-ckt stable] Patch "ALSA: hda - Set SKL+ hda controller power at freeze() and thaw()" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ALSA: hda - Set SKL+ hda controller power at freeze() and thaw()

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 4c3517c0ff14751c88fccbf0193095c9f129ce80 Mon Sep 17 00:00:00 2001
From: Xiong Zhang <xiong.y.zhang at intel.com>
Date: Fri, 18 Dec 2015 13:29:18 +0800
Subject: ALSA: hda - Set SKL+ hda controller power at freeze() and thaw()

commit 3e6db33aaf1d42a30339f831ec4850570d6cc7a3 upstream.

It takes three minutes to enter into hibernation on some OEM SKL
machines and we see many codec spurious response after thaw() opertion.
This is because HDA is still in D0 state after freeze() call and
pci_pm_freeze/pci_pm_freeze_noirq() don't set D3 hot in pci_bus driver.
It seems bios still access HDA when system enter into freeze state,
HDA will receive codec response interrupt immediately after thaw() call.
Because of this unexpected interrupt, HDA enter into a abnormal
state and slow down the system enter into hibernation.

In this patch, we put HDA into D3 hot state in azx_freeze_noirq() and
put HDA into D0 state in azx_thaw_noirq().

V2: Only apply this fix to SKL+
    Fix compile error when CONFIG_PM_SLEEP isn't defined

[Yet another fix for CONFIG_PM_SLEEP ifdef and the additional comment
 by tiwai]

Signed-off-by: Xiong Zhang <xiong.y.zhang at intel.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/pci/hda/hda_intel.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 4d2cbe2..de2b2e2 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -927,6 +927,36 @@ static int azx_resume(struct device *dev)
 }
 #endif /* CONFIG_PM_SLEEP || SUPPORT_VGA_SWITCHEROO */

+#ifdef CONFIG_PM_SLEEP
+/* put codec down to D3 at hibernation for Intel SKL+;
+ * otherwise BIOS may still access the codec and screw up the driver
+ */
+#define IS_SKL(pci) ((pci)->vendor == 0x8086 && (pci)->device == 0xa170)
+#define IS_SKL_LP(pci) ((pci)->vendor == 0x8086 && (pci)->device == 0x9d70)
+#define IS_BXT(pci) ((pci)->vendor == 0x8086 && (pci)->device == 0x5a98)
+#define IS_SKL_PLUS(pci) (IS_SKL(pci) || IS_SKL_LP(pci) || IS_BXT(pci))
+
+static int azx_freeze_noirq(struct device *dev)
+{
+	struct pci_dev *pci = to_pci_dev(dev);
+
+	if (IS_SKL_PLUS(pci))
+		pci_set_power_state(pci, PCI_D3hot);
+
+	return 0;
+}
+
+static int azx_thaw_noirq(struct device *dev)
+{
+	struct pci_dev *pci = to_pci_dev(dev);
+
+	if (IS_SKL_PLUS(pci))
+		pci_set_power_state(pci, PCI_D0);
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
 #ifdef CONFIG_PM
 static int azx_runtime_suspend(struct device *dev)
 {
@@ -1036,6 +1066,10 @@ static int azx_runtime_idle(struct device *dev)

 static const struct dev_pm_ops azx_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(azx_suspend, azx_resume)
+#ifdef CONFIG_PM_SLEEP
+	.freeze_noirq = azx_freeze_noirq,
+	.thaw_noirq = azx_thaw_noirq,
+#endif
 	SET_RUNTIME_PM_OPS(azx_runtime_suspend, azx_runtime_resume, azx_runtime_idle)
 };

--
1.9.1