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authorSameer Pujar <spujar@nvidia.com>2020-05-04 11:16:15 +0300
committerTakashi Iwai <tiwai@suse.de>2020-05-04 12:51:23 +0300
commit67ae482a59e951c346b5a55a756504bc58ce7cfa (patch)
tree516c3ff2664459e741b39e5ddd8d5411a4d71f0b /sound/hda
parentbb9b02a4589cee66cdb92eb9b7191d6557afdd6f (diff)
downloadlinux-67ae482a59e951c346b5a55a756504bc58ce7cfa.tar.xz
ALSA: hda: add member to store ratio for stripe control
Stripe control programming is governed by following formula, which is referenced from the HD Audio specification(Revision 1.0a). { ((num_channels * bits_per_sample) / number of SDOs) >= 8 } Currently above is implemented in snd_hdac_get_stream_stripe_ctl(). This patch introduces a structure member to store the default factor of '8'. If any HW wants to use a different value, this member can be easily updated. Signed-off-by: Sameer Pujar <spujar@nvidia.com> Link: https://lore.kernel.org/r/1588580176-2801-3-git-send-email-spujar@nvidia.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/hda')
-rw-r--r--sound/hda/hdac_controller.c12
-rw-r--r--sound/hda/hdac_stream.c2
2 files changed, 13 insertions, 1 deletions
diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index bc4a8b606020..ac15aa357fbd 100644
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -527,6 +527,18 @@ bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset)
}
bus->chip_init = true;
+
+ /*
+ * Default value of '8' is as per the HD audio specification (Rev 1.0a).
+ * Following relation is used to derive STRIPE control value.
+ * For sample rate <= 48K:
+ * { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
+ * For sample rate > 48K:
+ * { ((num_channels * bits_per_sample * rate/48000) /
+ * number of SDOs) >= 8 }
+ */
+ bus->sdo_limit = 8;
+
return true;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_init_chip);
diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c
index a314b03b4a4c..a38a2af1654f 100644
--- a/sound/hda/hdac_stream.c
+++ b/sound/hda/hdac_stream.c
@@ -38,7 +38,7 @@ int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus,
else
value = (channels * bits_per_sample) / sdo_line;
- if (value >= 8)
+ if (value >= bus->sdo_limit)
break;
}