ALSA: hda - Update BCLK also at hotplug for i915 HSW/BDW

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
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/sound/hda_i915.h b/include/sound/hda_i915.h
index fa341fcb5829ab80114e6b22d69fc06856259cbd..f5842bcd9c94ca633a2673d7a4bdceac76423364 100644 (file)
--- 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(struct hdac_bus *bus, bool enable)
 {
        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)

diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
index 54babe1c0b1679b97ae43c3b745f0843b15ccfde..607bbeaebddf784aadb062c7b3934b4fa506c1e0 100644 (file)
--- 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_bus *bus, bool enable)
 }
 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:

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 637b8a0e2a91d3ab9b73ddc8a4b9fc4a24303e00..9a0d1445ca5cf85c774a6f4e4be1d5a44770adad 100644 (file)
--- 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 *val, const struct kernel_param *kp)
 #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 device *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 *chip)
        /* 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);
 

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 40933aa33afe337821570176e93cc9cbb71a8c28..1483f85999ecd82d1b9215f5a634011819fd368a 100644 (file)
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2232,6 +2232,7 @@ static void intel_pin_eld_notify(void *audio_ptr, int port)
        if (atomic_read(&(codec)->core.in_pm))
                return;
 
+       snd_hdac_i915_set_bclk(&codec->bus->core);
        check_presence_and_report(codec, pin_nid);
 }