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ALSA: ump: Transmit RPN/NRPN message at each MSB/LSB data reception

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The UMP 1.1 spec says that an RPN/NRPN should be sent when one of the
following occurs:
* a CC 38 is received
* a subsequent CC 6 is received
* a CC 98, 99, 100, and 101 is received, indicating the last RPN/NRPN
  message has ended and a new one has started

That said, we should send a partial data even if it's not fully
filled.  Let's change the UMP conversion helper code to follow that
rule.

Link: https://patch.msgid.link/20240731130528.12600-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2024-07-31 15:05:22 +02:00
parent 3dab73ab92
commit e6ce8a28c7
2 changed files with 33 additions and 17 deletions
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1
include/sound/ump_convert.h
View File

@ -13,6 +13,7 @@ struct ump_cvt_to_ump_bank {
unsigned char cc_nrpn_msb, cc_nrpn_lsb;
unsigned char cc_data_msb, cc_data_lsb;
unsigned char cc_bank_msb, cc_bank_lsb;
bool cc_data_msb_set, cc_data_lsb_set;
};
/* context for converting from MIDI1 byte stream to UMP packet */

49
sound/core/ump_convert.c
View File

@ -287,25 +287,37 @@ static int cvt_legacy_system_to_ump(struct ump_cvt_to_ump *cvt,
return 4;
}
static void fill_rpn(struct ump_cvt_to_ump_bank *cc,
union snd_ump_midi2_msg *midi2)
static int fill_rpn(struct ump_cvt_to_ump_bank *cc,
union snd_ump_midi2_msg *midi2,
bool flush)
{
if (!(cc->cc_data_lsb_set || cc->cc_data_msb_set))
return 0; // skip
/* when not flushing, wait for complete data set */
if (!flush && (!cc->cc_data_lsb_set || !cc->cc_data_msb_set))
return 0; // skip
if (cc->rpn_set) {
midi2->rpn.status = UMP_MSG_STATUS_RPN;
midi2->rpn.bank = cc->cc_rpn_msb;
midi2->rpn.index = cc->cc_rpn_lsb;
cc->rpn_set = 0;
cc->cc_rpn_msb = cc->cc_rpn_lsb = 0;
} else {
} else if (cc->nrpn_set) {
midi2->rpn.status = UMP_MSG_STATUS_NRPN;
midi2->rpn.bank = cc->cc_nrpn_msb;
midi2->rpn.index = cc->cc_nrpn_lsb;
cc->nrpn_set = 0;
cc->cc_nrpn_msb = cc->cc_nrpn_lsb = 0;
} else {
return 0; // skip
}
midi2->rpn.data = upscale_14_to_32bit((cc->cc_data_msb << 7) |
cc->cc_data_lsb);
cc->rpn_set = 0;
cc->nrpn_set = 0;
cc->cc_rpn_msb = cc->cc_rpn_lsb = 0;
cc->cc_data_msb = cc->cc_data_lsb = 0;
cc->cc_data_msb_set = cc->cc_data_lsb_set = 0;
return 1;
}
/* convert to a MIDI 1.0 Channel Voice message */
@ -318,6 +330,7 @@ static int cvt_legacy_cmd_to_ump(struct ump_cvt_to_ump *cvt,
struct ump_cvt_to_ump_bank *cc;
union snd_ump_midi2_msg *midi2 = (union snd_ump_midi2_msg *)data;
unsigned char status, channel;
int ret;
BUILD_BUG_ON(sizeof(union snd_ump_midi1_msg) != 4);
BUILD_BUG_ON(sizeof(union snd_ump_midi2_msg) != 8);
@ -358,24 +371,29 @@ static int cvt_legacy_cmd_to_ump(struct ump_cvt_to_ump *cvt,
case UMP_MSG_STATUS_CC:
switch (buf[1]) {
case UMP_CC_RPN_MSB:
ret = fill_rpn(cc, midi2, true);
cc->rpn_set = 1;
cc->cc_rpn_msb = buf[2];
return 0; // skip
return ret;
case UMP_CC_RPN_LSB:
ret = fill_rpn(cc, midi2, true);
cc->rpn_set = 1;
cc->cc_rpn_lsb = buf[2];
return 0; // skip
return ret;
case UMP_CC_NRPN_MSB:
ret = fill_rpn(cc, midi2, true);
cc->nrpn_set = 1;
cc->cc_nrpn_msb = buf[2];
return 0; // skip
return ret;
case UMP_CC_NRPN_LSB:
ret = fill_rpn(cc, midi2, true);
cc->nrpn_set = 1;
cc->cc_nrpn_lsb = buf[2];
return 0; // skip
return ret;
case UMP_CC_DATA:
cc->cc_data_msb_set = 1;
cc->cc_data_msb = buf[2];
return 0; // skip
return fill_rpn(cc, midi2, false);
case UMP_CC_BANK_SELECT:
cc->bank_set = 1;
cc->cc_bank_msb = buf[2];
@ -385,12 +403,9 @@ static int cvt_legacy_cmd_to_ump(struct ump_cvt_to_ump *cvt,
cc->cc_bank_lsb = buf[2];
return 0; // skip
case UMP_CC_DATA_LSB:
cc->cc_data_lsb_set = 1;
cc->cc_data_lsb = buf[2];
if (cc->rpn_set || cc->nrpn_set)
fill_rpn(cc, midi2);
else
return 0; // skip
break;
return fill_rpn(cc, midi2, false);
default:
midi2->cc.index = buf[1];
midi2->cc.data = upscale_7_to_32bit(buf[2]);