Merge tag 'sound-3.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"This batch contains two fixes for FireWire lib module and a quirk for
yet another Logitech WebCam. The former is the fixes for MIDI
handling I forgot to pick up during the merge window. All the fixed
code is pretty local and shouldn't give any regressions"
* tag 'sound-3.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Add mic volume fix quirk for Logitech Webcam C210
ALSA: firewire-lib: limit the MIDI data rate
ALSA: firewire-lib: remove rx_blocks_for_midi quirk
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index 3badc70..0d58018 100644
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -21,7 +21,19 @@
#define CYCLES_PER_SECOND 8000
#define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
-#define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */
+/*
+ * Nominally 3125 bytes/second, but the MIDI port's clock might be
+ * 1% too slow, and the bus clock 100 ppm too fast.
+ */
+#define MIDI_BYTES_PER_SECOND 3093
+
+/*
+ * Several devices look only at the first eight data blocks.
+ * In any case, this is more than enough for the MIDI data rate.
+ */
+#define MAX_MIDI_RX_BLOCKS 8
+
+#define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */
/* isochronous header parameters */
#define ISO_DATA_LENGTH_SHIFT 16
@@ -78,8 +90,6 @@
s->callbacked = false;
s->sync_slave = NULL;
- s->rx_blocks_for_midi = UINT_MAX;
-
return 0;
}
EXPORT_SYMBOL(amdtp_stream_init);
@@ -222,6 +232,14 @@
for (i = 0; i < pcm_channels; i++)
s->pcm_positions[i] = i;
s->midi_position = s->pcm_channels;
+
+ /*
+ * We do not know the actual MIDI FIFO size of most devices. Just
+ * assume two bytes, i.e., one byte can be received over the bus while
+ * the previous one is transmitted over MIDI.
+ * (The value here is adjusted for midi_ratelimit_per_packet().)
+ */
+ s->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1;
}
EXPORT_SYMBOL(amdtp_stream_set_parameters);
@@ -463,6 +481,36 @@
}
}
+/*
+ * To avoid sending MIDI bytes at too high a rate, assume that the receiving
+ * device has a FIFO, and track how much it is filled. This values increases
+ * by one whenever we send one byte in a packet, but the FIFO empties at
+ * a constant rate independent of our packet rate. One packet has syt_interval
+ * samples, so the number of bytes that empty out of the FIFO, per packet(!),
+ * is MIDI_BYTES_PER_SECOND * syt_interval / sample_rate. To avoid storing
+ * fractional values, the values in midi_fifo_used[] are measured in bytes
+ * multiplied by the sample rate.
+ */
+static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port)
+{
+ int used;
+
+ used = s->midi_fifo_used[port];
+ if (used == 0) /* common shortcut */
+ return true;
+
+ used -= MIDI_BYTES_PER_SECOND * s->syt_interval;
+ used = max(used, 0);
+ s->midi_fifo_used[port] = used;
+
+ return used < s->midi_fifo_limit;
+}
+
+static void midi_rate_use_one_byte(struct amdtp_stream *s, unsigned int port)
+{
+ s->midi_fifo_used[port] += amdtp_rate_table[s->sfc];
+}
+
static void amdtp_fill_midi(struct amdtp_stream *s,
__be32 *buffer, unsigned int frames)
{
@@ -470,16 +518,21 @@
u8 *b;
for (f = 0; f < frames; f++) {
- buffer[s->midi_position] = 0;
b = (u8 *)&buffer[s->midi_position];
port = (s->data_block_counter + f) % 8;
- if ((f >= s->rx_blocks_for_midi) ||
- (s->midi[port] == NULL) ||
- (snd_rawmidi_transmit(s->midi[port], b + 1, 1) <= 0))
- b[0] = 0x80;
- else
+ if (f < MAX_MIDI_RX_BLOCKS &&
+ midi_ratelimit_per_packet(s, port) &&
+ s->midi[port] != NULL &&
+ snd_rawmidi_transmit(s->midi[port], &b[1], 1) == 1) {
+ midi_rate_use_one_byte(s, port);
b[0] = 0x81;
+ } else {
+ b[0] = 0x80;
+ b[1] = 0;
+ }
+ b[2] = 0;
+ b[3] = 0;
buffer += s->data_block_quadlets;
}
diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h
index e6e8926..8a03a91 100644
--- a/sound/firewire/amdtp.h
+++ b/sound/firewire/amdtp.h
@@ -148,13 +148,12 @@
bool double_pcm_frames;
struct snd_rawmidi_substream *midi[AMDTP_MAX_CHANNELS_FOR_MIDI * 8];
+ int midi_fifo_limit;
+ int midi_fifo_used[AMDTP_MAX_CHANNELS_FOR_MIDI * 8];
/* quirk: fixed interval of dbc between previos/current packets. */
unsigned int tx_dbc_interval;
- /* quirk: the first count of data blocks in an rx packet for MIDI */
- unsigned int rx_blocks_for_midi;
-
bool callbacked;
wait_queue_head_t callback_wait;
struct amdtp_stream *sync_slave;
diff --git a/sound/firewire/bebob/bebob_stream.c b/sound/firewire/bebob/bebob_stream.c
index 1aab0a32..0ebcabf 100644
--- a/sound/firewire/bebob/bebob_stream.c
+++ b/sound/firewire/bebob/bebob_stream.c
@@ -484,13 +484,6 @@
amdtp_stream_destroy(&bebob->rx_stream);
destroy_both_connections(bebob);
}
- /*
- * The firmware for these devices ignore MIDI messages in more than
- * first 8 data blocks of an received AMDTP packet.
- */
- if (bebob->spec == &maudio_fw410_spec ||
- bebob->spec == &maudio_special_spec)
- bebob->rx_stream.rx_blocks_for_midi = 8;
end:
return err;
}
diff --git a/sound/firewire/fireworks/fireworks_stream.c b/sound/firewire/fireworks/fireworks_stream.c
index b985fc5..4f440e1 100644
--- a/sound/firewire/fireworks/fireworks_stream.c
+++ b/sound/firewire/fireworks/fireworks_stream.c
@@ -179,11 +179,6 @@
destroy_stream(efw, &efw->tx_stream);
goto end;
}
- /*
- * Fireworks ignores MIDI messages in more than first 8 data
- * blocks of an received AMDTP packet.
- */
- efw->rx_stream.rx_blocks_for_midi = 8;
/* set IEC61883 compliant mode (actually not fully compliant...) */
err = snd_efw_command_set_tx_mode(efw, SND_EFW_TRANSPORT_MODE_IEC61883);
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 41650d5..3e2ef61 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -913,6 +913,7 @@
case USB_ID(0x046d, 0x0807): /* Logitech Webcam C500 */
case USB_ID(0x046d, 0x0808):
case USB_ID(0x046d, 0x0809):
+ case USB_ID(0x046d, 0x0819): /* Logitech Webcam C210 */
case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */