From 67ae482a59e951c346b5a55a756504bc58ce7cfa Mon Sep 17 00:00:00 2001 From: Sameer Pujar Date: Mon, 4 May 2020 13:46:15 +0530 Subject: 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 Link: https://lore.kernel.org/r/1588580176-2801-3-git-send-email-spujar@nvidia.com Signed-off-by: Takashi Iwai --- sound/hda/hdac_controller.c | 12 ++++++++++++ sound/hda/hdac_stream.c | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-) (limited to 'sound/hda') 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; } -- cgit v1.2.3