[PATCH 6.10 07/29] usb: gadget: midi2: Fix incorrect default MIDI2 protocol setup

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai@suse.de>

commit 3eb27d3e32c78badbc4db6ae76614b5961e32291 upstream.

The MIDI2 gadget driver handled the default MIDI protocol version
incorrectly due to the confusion of the protocol version passed via
configfs (either 1 or 2) and UMP protocol bits (0x100 / 0x200).
As a consequence, the default protocol always resulted in MIDI1.

This patch addresses the misunderstanding of the protocol handling.

Fixes: 29ee7a4dddd5 ("usb: gadget: midi2: Add configfs support")
Cc: stable <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240708095719.25627-1-tiwai@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/gadget/function/f_midi2.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

--- a/drivers/usb/gadget/function/f_midi2.c
+++ b/drivers/usb/gadget/function/f_midi2.c
@@ -150,6 +150,9 @@ struct f_midi2 {
 
 #define func_to_midi2(f)	container_of(f, struct f_midi2, func)
 
+/* convert from MIDI protocol number (1 or 2) to SNDRV_UMP_EP_INFO_PROTO_* */
+#define to_ump_protocol(v)	(((v) & 3) << 8)
+
 /* get EP name string */
 static const char *ump_ep_name(const struct f_midi2_ep *ep)
 {
@@ -564,8 +567,7 @@ static void reply_ump_stream_ep_config(s
 		.status = UMP_STREAM_MSG_STATUS_STREAM_CFG,
 	};
 
-	if ((ep->info.protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI_MASK) ==
-	    SNDRV_UMP_EP_INFO_PROTO_MIDI2)
+	if (ep->info.protocol == 2)
 		rep.protocol = UMP_STREAM_MSG_EP_INFO_CAP_MIDI2 >> 8;
 	else
 		rep.protocol = UMP_STREAM_MSG_EP_INFO_CAP_MIDI1 >> 8;
@@ -627,13 +629,13 @@ static void process_ump_stream_msg(struc
 		return;
 	case UMP_STREAM_MSG_STATUS_STREAM_CFG_REQUEST:
 		if (*data & UMP_STREAM_MSG_EP_INFO_CAP_MIDI2) {
-			ep->info.protocol = SNDRV_UMP_EP_INFO_PROTO_MIDI2;
+			ep->info.protocol = 2;
 			DBG(midi2, "Switching Protocol to MIDI2\n");
 		} else {
-			ep->info.protocol = SNDRV_UMP_EP_INFO_PROTO_MIDI1;
+			ep->info.protocol = 1;
 			DBG(midi2, "Switching Protocol to MIDI1\n");
 		}
-		snd_ump_switch_protocol(ep->ump, ep->info.protocol);
+		snd_ump_switch_protocol(ep->ump, to_ump_protocol(ep->info.protocol));
 		reply_ump_stream_ep_config(ep);
 		return;
 	case UMP_STREAM_MSG_STATUS_FB_DISCOVERY:
@@ -1065,7 +1067,8 @@ static void f_midi2_midi1_ep_out_complet
 		group = midi2->out_cable_mapping[cable].group;
 		bytes = midi1_packet_bytes[*buf & 0x0f];
 		for (c = 0; c < bytes; c++) {
-			snd_ump_convert_to_ump(cvt, group, ep->info.protocol,
+			snd_ump_convert_to_ump(cvt, group,
+					       to_ump_protocol(ep->info.protocol),
 					       buf[c + 1]);
 			if (cvt->ump_bytes) {
 				snd_ump_receive(ep->ump, cvt->ump,
@@ -1375,7 +1378,7 @@ static void assign_block_descriptors(str
 			desc->nNumGroupTrm = b->num_groups;
 			desc->iBlockItem = ep->blks[blk].string_id;
 
-			if (ep->info.protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI2)
+			if (ep->info.protocol == 2)
 				desc->bMIDIProtocol = USB_MS_MIDI_PROTO_2_0;
 			else
 				desc->bMIDIProtocol = USB_MS_MIDI_PROTO_1_0_128;
@@ -1552,7 +1555,7 @@ static int f_midi2_create_card(struct f_
 		if (midi2->info.static_block)
 			ump->info.flags |= SNDRV_UMP_EP_INFO_STATIC_BLOCKS;
 		ump->info.protocol_caps = (ep->info.protocol_caps & 3) << 8;
-		ump->info.protocol = (ep->info.protocol & 3) << 8;
+		ump->info.protocol = to_ump_protocol(ep->info.protocol);
 		ump->info.version = 0x0101;
 		ump->info.family_id = ep->info.family;
 		ump->info.model_id = ep->info.model;