Patch "ALSA: seq: ump: Explicitly reset RPN with Null RPN" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ALSA: seq: ump: Explicitly reset RPN with Null RPN

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     alsa-seq-ump-explicitly-reset-rpn-with-null-rpn.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 80fe0d94469aa71a96014a9cb0b40f07ab7af207
Author: Takashi Iwai <tiwai@xxxxxxx>
Date:   Wed Jul 31 15:05:26 2024 +0200

    ALSA: seq: ump: Explicitly reset RPN with Null RPN
    
    [ Upstream commit 98ea612dd1150adb61cd2a0e93875e1cc77e6b87 ]
    
    RPN with 127:127 is treated as a Null RPN, just to reset the
    parameters, and it's not translated to MIDI2.  Although the current
    code can work as is in most cases, better to implement the RPN reset
    explicitly for Null message.
    
    Link: https://patch.msgid.link/20240731130528.12600-6-tiwai@xxxxxxx
    Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/sound/core/seq/seq_ump_convert.c b/sound/core/seq/seq_ump_convert.c
index 7ca62667f28d3..4dd540cbb1cbb 100644
--- a/sound/core/seq/seq_ump_convert.c
+++ b/sound/core/seq/seq_ump_convert.c
@@ -789,6 +789,15 @@ static int paf_ev_to_ump_midi2(const struct snd_seq_event *event,
 	return 1;
 }
 
+static void reset_rpn(struct ump_cvt_to_ump_bank *cc)
+{
+	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;
+}
+
 /* set up the MIDI2 RPN/NRPN packet data from the parsed info */
 static int fill_rpn(struct ump_cvt_to_ump_bank *cc,
 		    union snd_ump_midi2_msg *data,
@@ -817,11 +826,7 @@ static int fill_rpn(struct ump_cvt_to_ump_bank *cc,
 					     cc->cc_data_lsb);
 	data->rpn.channel = channel;
 
-	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;
+	reset_rpn(cc);
 	return 1;
 }
 
@@ -843,11 +848,15 @@ static int cc_ev_to_ump_midi2(const struct snd_seq_event *event,
 		ret = fill_rpn(cc, data, channel, true);
 		cc->rpn_set = 1;
 		cc->cc_rpn_msb = val;
+		if (cc->cc_rpn_msb == 0x7f && cc->cc_rpn_lsb == 0x7f)
+			reset_rpn(cc);
 		return ret;
 	case UMP_CC_RPN_LSB:
 		ret = fill_rpn(cc, data, channel, true);
 		cc->rpn_set = 1;
 		cc->cc_rpn_lsb = val;
+		if (cc->cc_rpn_msb == 0x7f && cc->cc_rpn_lsb == 0x7f)
+			reset_rpn(cc);
 		return ret;
 	case UMP_CC_NRPN_MSB:
 		ret = fill_rpn(cc, data, channel, true);
@@ -961,6 +970,8 @@ static int ctrl14_ev_to_ump_midi2(const struct snd_seq_event *event,
 		cc->cc_rpn_msb = msb;
 		cc->cc_rpn_lsb = lsb;
 		cc->rpn_set = 1;
+		if (cc->cc_rpn_msb == 0x7f && cc->cc_rpn_lsb == 0x7f)
+			reset_rpn(cc);
 		return ret;
 	case UMP_CC_NRPN_MSB:
 	case UMP_CC_NRPN_LSB: