[PATCH 4.5 044/200] ALSA: hda - Update BCLK also at hotplug for i915 HSW/BDW

Greg Kroah-Hartman
2016-05-03T01:20:39Z

From: Takashi Iwai <tiwai@suse.de>

commit bb03ed216370cb021f377f923471e56d1de3ff5d upstream.

The recent bug report suggests that BCLK setup for i915 HSW/BDW needs
to be updated at each HDMI hotplug, not only at initialization and
resume. That is, we need to update HSW_EM4 and HSW_EM5 registers at
ELD notification, too. Otherwise the HDMI audio may be out of sync
and played in a wrong pitch.

However, the HDA codec driver has no access to the controller
registers, and currently the code managing these registers is in
hda_intel.c, i.e. local to the controller driver. For allowing the
explicit BCLK update from the codec driver, as in this patch, the
former haswell_set_bclk() in hda_intel.c is moved to hdac_i915.c and
exposed as snd_hdac_i915_set_bclk(). This is called from both the HDA
controller driver and intel_pin_eld_notify() in HDMI codec driver.

Along with this change, snd_hdac_get_display_clk() gets dropped as
it's no longer used.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91410
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/sound/hda_i915.h | 5 +--
sound/hda/hdac_i915.c | 62 +++++++++++++++++++++++++++++++++++++--------
sound/pci/hda/hda_intel.c | 56 ++--------------------------------------
sound/pci/hda/patch_hdmi.c | 1
4 files changed, 58 insertions(+), 66 deletions(-)

--- a/include/sound/hda_i915.h
+++ b/include/sound/hda_i915.h
@@ -9,7 +9,7 @@
#ifdef CONFIG_SND_HDA_I915
int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable);
int snd_hdac_display_power(struct hdac_bus *bus, bool enable);
-int snd_hdac_get_display_clk(struct hdac_bus *bus);
+void snd_hdac_i915_set_bclk(struct hdac_bus *bus);
int snd_hdac_sync_audio_rate(struct hdac_bus *bus, hda_nid_t nid, int rate);
int snd_hdac_acomp_get_eld(struct hdac_bus *bus, hda_nid_t nid,
bool *audio_enabled, char *buffer, int max_bytes);
@@ -25,9 +25,8 @@ static inline int snd_hdac_display_power
{
return 0;
}
-static inline int snd_hdac_get_display_clk(struct hdac_bus *bus)
+static inline void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
{
- return 0;
}
static inline int snd_hdac_sync_audio_rate(struct hdac_bus *bus, hda_nid_t nid,
int rate)
--- a/sound/hda/hdac_i915.c
+++ b/sound/hda/hdac_i915.c
@@ -20,6 +20,7 @@
#include <sound/core.h>
#include <sound/hdaudio.h>
#include <sound/hda_i915.h>
+#include <sound/hda_register.h>

static struct i915_audio_component *hdac_acomp;

@@ -97,26 +98,65 @@ int snd_hdac_display_power(struct hdac_b
}
EXPORT_SYMBOL_GPL(snd_hdac_display_power);

+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
+ ((pci)->device == 0x0c0c) || \
+ ((pci)->device == 0x0d0c) || \
+ ((pci)->device == 0x160c))
+
/**
- * snd_hdac_get_display_clk - Get CDCLK in kHz
+ * snd_hdac_i915_set_bclk - Reprogram BCLK for HSW/BDW
* @bus: HDA core bus
*
- * This function is supposed to be used only by a HD-audio controller
- * driver that needs the interaction with i915 graphics.
+ * Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK
+ * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value)
+ * are used to convert CDClk (Core Display Clock) to 24MHz BCLK:
+ * BCLK = CDCLK * M / N
+ * The values will be lost when the display power well is disabled and need to
+ * be restored to avoid abnormal playback speed.
*
- * This function queries CDCLK value in kHz from the graphics driver and
- * returns the value. A negative code is returned in error.
+ * Call this function at initializing and changing power well, as well as
+ * at ELD notifier for the hotplug.
*/
-int snd_hdac_get_display_clk(struct hdac_bus *bus)
+void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
{
struct i915_audio_component *acomp = bus->audio_component;
+ struct pci_dev *pci = to_pci_dev(bus->dev);
+ int cdclk_freq;
+ unsigned int bclk_m, bclk_n;
+
+ if (!acomp || !acomp->ops || !acomp->ops->get_cdclk_freq)
+ return; /* only for i915 binding */
+ if (!CONTROLLER_IN_GPU(pci))
+ return; /* only HSW/BDW */
+
+ cdclk_freq = acomp->ops->get_cdclk_freq(acomp->dev);
+ switch (cdclk_freq) {
+ case 337500:
+ bclk_m = 16;
+ bclk_n = 225;
+ break;
+
+ case 450000:
+ default: /* default CDCLK 450MHz */
+ bclk_m = 4;
+ bclk_n = 75;
+ break;
+
+ case 540000:
+ bclk_m = 4;
+ bclk_n = 90;
+ break;
+
+ case 675000:
+ bclk_m = 8;
+ bclk_n = 225;
+ break;
+ }

- if (!acomp || !acomp->ops)
- return -ENODEV;
-
- return acomp->ops->get_cdclk_freq(acomp->dev);
+ snd_hdac_chip_writew(bus, HSW_EM4, bclk_m);
+ snd_hdac_chip_writew(bus, HSW_EM5, bclk_n);
}
-EXPORT_SYMBOL_GPL(snd_hdac_get_display_clk);
+EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);

/* There is a fixed mapping between audio pin node and display port
* on current Intel platforms:
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -857,50 +857,6 @@ static int param_set_xint(const char *va
#define azx_del_card_list(chip) /* NOP */
#endif /* CONFIG_PM */

-/* Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK
- * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value)
- * are used to convert CDClk (Core Display Clock) to 24MHz BCLK:
- * BCLK = CDCLK * M / N
- * The values will be lost when the display power well is disabled and need to
- * be restored to avoid abnormal playback speed.
- */
-static void haswell_set_bclk(struct hda_intel *hda)
-{
- struct azx *chip = &hda->chip;
- int cdclk_freq;
- unsigned int bclk_m, bclk_n;
-
- if (!hda->need_i915_power)
- return;
-
- cdclk_freq = snd_hdac_get_display_clk(azx_bus(chip));
- switch (cdclk_freq) {
- case 337500:
- bclk_m = 16;
- bclk_n = 225;
- break;
-
- case 450000:
- default: /* default CDCLK 450MHz */
- bclk_m = 4;
- bclk_n = 75;
- break;
-
- case 540000:
- bclk_m = 4;
- bclk_n = 90;
- break;
-
- case 675000:
- bclk_m = 8;
- bclk_n = 225;
- break;
- }
-
- azx_writew(chip, HSW_EM4, bclk_m);
- azx_writew(chip, HSW_EM5, bclk_n);
-}
-
#if defined(CONFIG_PM_SLEEP) || defined(SUPPORT_VGA_SWITCHEROO)
/*
* power management
@@ -958,7 +914,7 @@ static int azx_resume(struct device *dev
if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL
&& hda->need_i915_power) {
snd_hdac_display_power(azx_bus(chip), true);
- haswell_set_bclk(hda);
+ snd_hdac_i915_set_bclk(azx_bus(chip));
}
if (chip->msi)
if (pci_enable_msi(pci) < 0)
@@ -1058,7 +1014,7 @@ static int azx_runtime_resume(struct dev
bus = azx_bus(chip);
if (hda->need_i915_power) {
snd_hdac_display_power(bus, true);
- haswell_set_bclk(hda);
+ snd_hdac_i915_set_bclk(bus);
} else {
/* toggle codec wakeup bit for STATESTS read */
snd_hdac_set_codec_wakeup(bus, true);
@@ -1796,12 +1752,8 @@ static int azx_first_init(struct azx *ch
/* initialize chip */
azx_init_pci(chip);

- if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
- struct hda_intel *hda;
-
- hda = container_of(chip, struct hda_intel, chip);
- haswell_set_bclk(hda);
- }
+ if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
+ snd_hdac_i915_set_bclk(bus);

hda_intel_init_chip(chip, (probe_only[dev] & 2) == 0);

--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2452,6 +2452,7 @@ static void intel_pin_eld_notify(void *a
if (atomic_read(&(codec)->core.in_pm))
return;

+ snd_hdac_i915_set_bclk(&codec->bus->core);
check_presence_and_report(codec, pin_nid);
}