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authorLibin Yang <libin.yang@intel.com>2017-04-06 14:18:21 +0300
committerTakashi Iwai <tiwai@suse.de>2017-04-07 11:39:21 +0300
commit1f9d3d98694b1cef93f99a54e6830e9717616ba6 (patch)
tree066f25d70d5769148a84b0187619af7e6b765242 /sound/pci
parentdde5bff5415953f9cc7413f1b1ceebcdfd583c07 (diff)
downloadlinux-1f9d3d98694b1cef93f99a54e6830e9717616ba6.tar.xz
ALSA: hda - set intel audio clock to a proper value
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> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/pci')
-rw-r--r--sound/pci/hda/hda_intel.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 64db6698214c..59ab34fa0bc8 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -540,6 +540,98 @@ static void bxt_reduce_dma_latency(struct azx *chip)
azx_writel(chip, VS_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);
@@ -565,6 +657,9 @@ 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 */