diff options
| author | Sameer Pujar <spujar@nvidia.com> | 2020-05-04 11:16:15 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2020-05-04 12:51:23 +0300 |
| commit | 67ae482a59e951c346b5a55a756504bc58ce7cfa (patch) | |
| tree | 516c3ff2664459e741b39e5ddd8d5411a4d71f0b | |
| parent | bb9b02a4589cee66cdb92eb9b7191d6557afdd6f (diff) | |
| download | linux-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>
| -rw-r--r-- | include/sound/hdaudio.h | 3 | ||||
| -rw-r--r-- | sound/hda/hdac_controller.c | 12 | ||||
| -rw-r--r-- | sound/hda/hdac_stream.c | 2 |
3 files changed, 16 insertions, 1 deletions
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h index affedc2801c4..d365297b3698 100644 --- a/include/sound/hdaudio.h +++ b/include/sound/hdaudio.h @@ -364,6 +364,9 @@ struct hdac_bus { /* link management */ struct list_head hlink_list; bool cmd_dma_state; + + /* factor used to derive STRIPE control value */ + unsigned int sdo_limit; }; int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev, 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; } |