From: Libin Yang libin.yang@intel.com
On some Intel platforms, the audio clock may not be set correctly with initial setting. This will cause the audio playback/capture rates wrong.
This patch checks the audio clock setting and will set it to a proper value if it is set incorrectly.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188411
Signed-off-by: Libin Yang libin.yang@intel.com --- sound/pci/hda/hda_intel.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index c8256a8..7b85132 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -539,6 +539,98 @@ static void bxt_reduce_dma_latency(struct azx *chip) azx_writel(chip, SKL_EM4L, val); }
+/* + * ML_LCAP bits: + * bit 0: 6 MHz Supported + * bit 1: 12 MHz Supported + * bit 2: 24 MHz Supported + * bit 3: 48 MHz Supported + * bit 4: 96 MHz Supported + * bit 5: 192 MHz Supported + */ +static int intel_get_lctl_scf(struct azx *chip) +{ + struct hdac_bus *bus = azx_bus(chip); + static int preferred_bits[] = { 2, 3, 1, 4, 5 }; + u32 val, t; + int i; + + val = readl(bus->mlcap + AZX_ML_BASE + AZX_REG_ML_LCAP); + + for (i = 0; i < ARRAY_SIZE(preferred_bits); i++) { + t = preferred_bits[i]; + if (val & (1 << t)) + return t; + } + + dev_warn(chip->card->dev, "set audio clock frequency to 6MHz"); + return 0; +} + +static int intel_ml_lctl_set_power(struct azx *chip, int state) +{ + struct hdac_bus *bus = azx_bus(chip); + u32 val; + int timeout; + + /* + * the codecs are sharing the first link setting by default + * If other links are enabled for stream, they need similar fix + */ + val = readl(bus->mlcap + AZX_ML_BASE + AZX_REG_ML_LCTL); + val &= ~AZX_MLCTL_SPA; + val |= state << AZX_MLCTL_SPA_SHIFT; + writel(val, bus->mlcap + AZX_ML_BASE + AZX_REG_ML_LCTL); + /* wait for CPA */ + timeout = 50; + while (timeout) { + if (((readl(bus->mlcap + AZX_ML_BASE + AZX_REG_ML_LCTL)) & + AZX_MLCTL_CPA) == (state << AZX_MLCTL_CPA_SHIFT)) + return 0; + timeout--; + udelay(10); + } + + return -1; +} + +static void intel_init_lctl(struct azx *chip) +{ + struct hdac_bus *bus = azx_bus(chip); + u32 val; + int ret; + + /* 0. check lctl register value is correct or not */ + val = readl(bus->mlcap + AZX_ML_BASE + AZX_REG_ML_LCTL); + /* if SCF is already set, let's use it */ + if ((val & ML_LCTL_SCF_MASK) != 0) + return; + + /* + * Before operating on SPA, CPA must match SPA. + * Any deviation may result in undefined behavior. + */ + if (((val & AZX_MLCTL_SPA) >> AZX_MLCTL_SPA_SHIFT) != + ((val & AZX_MLCTL_CPA) >> AZX_MLCTL_CPA_SHIFT)) + return; + + /* 1. turn link down: set SPA to 0 and wait CPA to 0 */ + ret = intel_ml_lctl_set_power(chip, 0); + udelay(100); + if (ret) + goto set_spa; + + /* 2. update SCF to select a properly audio clock*/ + val &= ~ML_LCTL_SCF_MASK; + val |= intel_get_lctl_scf(chip); + writel(val, bus->mlcap + AZX_ML_BASE + AZX_REG_ML_LCTL); + +set_spa: + /* 4. turn link up: set SPA to 1 and wait CPA to 1 */ + intel_ml_lctl_set_power(chip, 1); + udelay(100); +} + static void hda_intel_init_chip(struct azx *chip, bool full_reset) { struct hdac_bus *bus = azx_bus(chip); @@ -564,6 +656,9 @@ static void hda_intel_init_chip(struct azx *chip, bool full_reset) /* reduce dma latency to avoid noise */ if (IS_BXT(pci)) bxt_reduce_dma_latency(chip); + + if (bus->mlcap != NULL) + intel_init_lctl(chip); }
/* calculate runtime delay from LPIB */