[alsa-devel] [PATCH 5/8] ALSA: dice: purge generating channel cache
Takashi Sakamoto
o-takashi at sakamocchi.jp
Sun Nov 15 10:25:33 CET 2015
Dice hardware design doesn't allow drivers to read supported combination
between sampling transfer frequencies and the number of Multi bit linear
audio data channels. According to the design, ALSA dice driver changes
current sampling transfer frequency to generate the cache of combinations
at probing processing.
Although, this idea is worse because ALSA dice driver cannot handle bus
reset when processing driver's probe callback. The callbacks of drivers
for units on IEEE 1394 bus are serialized. For example, when processing
.probe callback in workqueue context, any other processing such as
.update is not executed. As a result, when processing probe callback,
the driver cannot handle bus reset.
Dice has a mechanism which we call as 'Dice notification'. After changing
sampling transfer frequency, the notification is transferred to an address
which a driver write to a register. At bus reset, the register is clear,
thus no notifications are transferred. In this case, after bus reset,
current sampling rate is not confirmed. To ensure changing sampling
transfer frequency, ALSA dice driver retries the change operation when
it receives no notification after the operation, though it's just a
workaround.
Unfortunately, most Dice based models generate bus reset several times
after powering on. ALSA Dice driver sometimes has wrong cache data for
the combination between sampling transfer frequencies and the number of
Multi bit linear audio data channel.
This commit purges processing cache data and related structure members. As
a result, users must set preferable sampling transfer frequency before
using ALSA PCM applications, as long as they want to start any PCM
substreams at the rate.
Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
sound/firewire/dice/dice-stream.c | 25 ++-------------
sound/firewire/dice/dice.c | 67 ++-------------------------------------
sound/firewire/dice/dice.h | 7 ----
3 files changed, 6 insertions(+), 93 deletions(-)
diff --git a/sound/firewire/dice/dice-stream.c b/sound/firewire/dice/dice-stream.c
index 4f74e3e..3462724 100644
--- a/sound/firewire/dice/dice-stream.c
+++ b/sound/firewire/dice/dice-stream.c
@@ -10,6 +10,7 @@
#include "dice.h"
#define CALLBACK_TIMEOUT 200
+#define NOTIFICATION_TIMEOUT_MS 100
const unsigned int snd_dice_rates[SND_DICE_RATES_COUNT] = {
/* mode 0 */
@@ -24,23 +25,6 @@ const unsigned int snd_dice_rates[SND_DICE_RATES_COUNT] = {
[6] = 192000,
};
-int snd_dice_stream_get_rate_mode(struct snd_dice *dice, unsigned int rate,
- unsigned int *mode)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(snd_dice_rates); i++) {
- if (!(dice->clock_caps & BIT(i)))
- continue;
- if (snd_dice_rates[i] != rate)
- continue;
-
- *mode = (i - 1) / 2;
- return 0;
- }
- return -EINVAL;
-}
-
static void release_resources(struct snd_dice *dice,
struct fw_iso_resources *resources)
{
@@ -100,13 +84,10 @@ static int start_stream(struct snd_dice *dice, struct amdtp_stream *stream,
{
struct fw_iso_resources *resources;
__be32 reg[2];
- unsigned int i, mode, pcm_chs, midi_ports;
+ unsigned int i, pcm_chs, midi_ports;
bool double_pcm_frames;
int err;
- err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
- if (err < 0)
- goto end;
if (stream == &dice->tx_stream) {
resources = &dice->tx_resources;
err = snd_dice_transaction_read_tx(dice, TX_NUMBER_AUDIO,
@@ -133,7 +114,7 @@ static int start_stream(struct snd_dice *dice, struct amdtp_stream *stream,
* For this quirk, blocking mode is required and PCM buffer size should
* be aligned to SYT_INTERVAL.
*/
- double_pcm_frames = mode > 1;
+ double_pcm_frames = rate > 96000;
if (double_pcm_frames) {
rate /= 2;
pcm_chs *= 2;
diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
index 0cda05c..7bc1167 100644
--- a/sound/firewire/dice/dice.c
+++ b/sound/firewire/dice/dice.c
@@ -111,65 +111,10 @@ end:
return err;
}
-static int highest_supported_mode_rate(struct snd_dice *dice,
- unsigned int mode, unsigned int *rate)
-{
- unsigned int i, m;
-
- for (i = ARRAY_SIZE(snd_dice_rates); i > 0; i--) {
- *rate = snd_dice_rates[i - 1];
- if (snd_dice_stream_get_rate_mode(dice, *rate, &m) < 0)
- continue;
- if (mode == m)
- break;
- }
- if (i == 0)
- return -EINVAL;
-
- return 0;
-}
-
-static int dice_read_mode_params(struct snd_dice *dice, unsigned int mode)
-{
- __be32 values[2];
- unsigned int rate;
- int err;
-
- if (highest_supported_mode_rate(dice, mode, &rate) < 0) {
- dice->tx_channels[mode] = 0;
- dice->tx_midi_ports[mode] = 0;
- dice->rx_channels[mode] = 0;
- dice->rx_midi_ports[mode] = 0;
- return 0;
- }
-
- err = snd_dice_transaction_set_rate(dice, rate);
- if (err < 0)
- return err;
-
- err = snd_dice_transaction_read_tx(dice, TX_NUMBER_AUDIO,
- values, sizeof(values));
- if (err < 0)
- return err;
-
- dice->tx_channels[mode] = be32_to_cpu(values[0]);
- dice->tx_midi_ports[mode] = be32_to_cpu(values[1]);
-
- err = snd_dice_transaction_read_rx(dice, RX_NUMBER_AUDIO,
- values, sizeof(values));
- if (err < 0)
- return err;
-
- dice->rx_channels[mode] = be32_to_cpu(values[0]);
- dice->rx_midi_ports[mode] = be32_to_cpu(values[1]);
-
- return 0;
-}
-
-static int dice_read_params(struct snd_dice *dice)
+static int check_clock_caps(struct snd_dice *dice)
{
__be32 value;
- int mode, err;
+ int err;
/* some very old firmwares don't tell about their clock support */
if (dice->clock_caps > 0) {
@@ -187,12 +132,6 @@ static int dice_read_params(struct snd_dice *dice)
CLOCK_CAP_SOURCE_INTERNAL;
}
- for (mode = 2; mode >= 0; --mode) {
- err = dice_read_mode_params(dice, mode);
- if (err < 0)
- return err;
- }
-
return 0;
}
@@ -277,7 +216,7 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
if (err < 0)
goto error;
- err = dice_read_params(dice);
+ err = check_clock_caps(dice);
if (err < 0)
goto error;
diff --git a/sound/firewire/dice/dice.h b/sound/firewire/dice/dice.h
index 101550ac..3d91a02 100644
--- a/sound/firewire/dice/dice.h
+++ b/sound/firewire/dice/dice.h
@@ -53,10 +53,6 @@ struct snd_dice {
unsigned int rsrv_offset;
unsigned int clock_caps;
- unsigned int tx_channels[3];
- unsigned int rx_channels[3];
- unsigned int tx_midi_ports[3];
- unsigned int rx_midi_ports[3];
struct fw_address_handler notification_handler;
int owner_generation;
@@ -166,9 +162,6 @@ void snd_dice_transaction_destroy(struct snd_dice *dice);
#define SND_DICE_RATES_COUNT 7
extern const unsigned int snd_dice_rates[SND_DICE_RATES_COUNT];
-int snd_dice_stream_get_rate_mode(struct snd_dice *dice,
- unsigned int rate, unsigned int *mode);
-
int snd_dice_stream_start_duplex(struct snd_dice *dice, unsigned int rate);
void snd_dice_stream_stop_duplex(struct snd_dice *dice);
int snd_dice_stream_init_duplex(struct snd_dice *dice);
--
2.5.0
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