From a07187c992be945ab561b370cbb49cfd72064c3c Mon Sep 17 00:00:00 2001 From: Mengdong Lin Date: Thu, 26 Jun 2014 18:45:16 +0800 Subject: ALSA: hda - restore BCLK M/N values when resuming HSW/BDW display controller For Intel Haswell/Broadwell display HD-A controller, the 24MHz HD-A link BCLK is converted from Core Display Clock (CDCLK): BCLK = CDCLK * M / N And there are two registers EM4 and EM5 to program M, N value respectively. The EM4/EM5 values will be lost and when the display power well is disabled. BIOS programs CDCLK selected by OEM and EM4/EM5, but BIOS has no idea about display power well on/off at runtime. So the M/N can be wrong if non-default CDCLK is used when the audio controller resumes, which results in an invalid BCLK and abnormal audio playback rate. So this patch saves and restores valid M/N values on controller suspend/resume. And 'struct hda_intel' is defined to contain standard HD-A 'struct azx' and Intel specific fields, as Takashi suggested. Signed-off-by: Mengdong Lin Cc: Signed-off-by: Takashi Iwai --- sound/pci/hda/hda_intel.c | 65 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 58 insertions(+), 7 deletions(-) diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 23fd6b9aecc..25753db9707 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -288,6 +288,24 @@ static char *driver_short_names[] = { [AZX_DRIVER_GENERIC] = "HD-Audio Generic", }; + +/* Intel HSW/BDW display HDA controller 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. + */ +#define ICH6_REG_EM4 0x100c +#define ICH6_REG_EM5 0x1010 + +struct hda_intel { + struct azx chip; + + /* HSW/BDW display HDA controller to restore BCLK from CDCLK */ + unsigned int bclk_m; + unsigned int bclk_n; +}; + + #ifdef CONFIG_X86 static void __mark_pages_wc(struct azx *chip, struct snd_dma_buffer *dmab, bool on) { @@ -580,6 +598,22 @@ static int param_set_xint(const char *val, const struct kernel_param *kp) #define azx_del_card_list(chip) /* NOP */ #endif /* CONFIG_PM */ +static void haswell_save_bclk(struct azx *chip) +{ + struct hda_intel *hda = container_of(chip, struct hda_intel, chip); + + hda->bclk_m = azx_readw(chip, EM4); + hda->bclk_n = azx_readw(chip, EM5); +} + +static void haswell_restore_bclk(struct azx *chip) +{ + struct hda_intel *hda = container_of(chip, struct hda_intel, chip); + + azx_writew(chip, EM4, hda->bclk_m); + azx_writew(chip, EM5, hda->bclk_n); +} + #if defined(CONFIG_PM_SLEEP) || defined(SUPPORT_VGA_SWITCHEROO) /* * power management @@ -606,6 +640,13 @@ static int azx_suspend(struct device *dev) free_irq(chip->irq, chip); chip->irq = -1; } + + /* Save BCLK M/N values before they become invalid in D3. + * Will test if display power well can be released now. + */ + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + haswell_save_bclk(chip); + if (chip->msi) pci_disable_msi(chip->pci); pci_disable_device(pci); @@ -625,8 +666,10 @@ static int azx_resume(struct device *dev) if (chip->disabled) return 0; - if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { hda_display_power(true); + haswell_restore_bclk(chip); + } pci_set_power_state(pci, PCI_D0); pci_restore_state(pci); if (pci_enable_device(pci) < 0) { @@ -670,8 +713,10 @@ static int azx_runtime_suspend(struct device *dev) azx_stop_chip(chip); azx_enter_link_reset(chip); azx_clear_irq_pending(chip); - if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { + haswell_save_bclk(chip); hda_display_power(false); + } return 0; } @@ -689,8 +734,10 @@ static int azx_runtime_resume(struct device *dev) if (!(chip->driver_caps & AZX_DCAPS_PM_RUNTIME)) return 0; - if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { hda_display_power(true); + haswell_restore_bclk(chip); + } /* Read STATESTS before controller reset */ status = azx_readw(chip, STATESTS); @@ -883,6 +930,8 @@ static int register_vga_switcheroo(struct azx *chip) static int azx_free(struct azx *chip) { struct pci_dev *pci = chip->pci; + struct hda_intel *hda = container_of(chip, struct hda_intel, chip); + int i; if ((chip->driver_caps & AZX_DCAPS_PM_RUNTIME) @@ -930,7 +979,7 @@ static int azx_free(struct azx *chip) hda_display_power(false); hda_i915_exit(); } - kfree(chip); + kfree(hda); return 0; } @@ -1174,6 +1223,7 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci, static struct snd_device_ops ops = { .dev_free = azx_dev_free, }; + struct hda_intel *hda; struct azx *chip; int err; @@ -1183,13 +1233,14 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci, if (err < 0) return err; - chip = kzalloc(sizeof(*chip), GFP_KERNEL); - if (!chip) { - dev_err(card->dev, "Cannot allocate chip\n"); + hda = kzalloc(sizeof(*hda), GFP_KERNEL); + if (!hda) { + dev_err(card->dev, "Cannot allocate hda\n"); pci_disable_device(pci); return -ENOMEM; } + chip = &hda->chip; spin_lock_init(&chip->reg_lock); mutex_init(&chip->open_mutex); chip->card = card; -- cgit v1.2.3-70-g09d2