usb: gadget: midi2: Fix incorrect default MIDI2 protocol setup

commit 3eb27d3 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: 29ee7a4 ("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>

Author: tiwai

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(struct f_midi2_ep *ep)
 		.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(struct f_midi2_ep *ep, const u32 *data)
 		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_complete(struct usb_ep *usb_ep,
 		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(struct f_midi2 *midi2,
 			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_midi2 *midi2)
 		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;