[PATCH] usb: gadget: f_midi: Fixing wMaxPacketSize exceeded issue during MIDI bind retries

[Faraz Ata]

From: Selvarasu Ganesan <selvarasu.g@xxxxxxxxxxx>

The current implementation sets the wMaxPacketSize of bulk in/out
endpoints to 1024 bytes at the end of the f_midi_bind function. However,
in cases where there is a failure in the first midi bind attempt,
consider rebinding. This scenario may encounter an f_midi_bind issue due
to the previous bind setting the bulk endpoint's wMaxPacketSize to 1024
bytes, which exceeds the ep->maxpacket_limit where configured TX/RX
FIFO's maxpacket size of 512 bytes for IN/OUT endpoints in support HS
speed only.
This commit addresses this issue by resetting the wMaxPacketSize before
endpoint claim

Fixes: 46decc82ffd5 ("usb: gadget: unconditionally allocate hs/ss descriptor in bind operation")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Selvarasu Ganesan <selvarasu.g@xxxxxxxxxxx>
---
 drivers/usb/gadget/function/f_midi.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 837fcdfa3840..5caa0e4eb07e 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -907,6 +907,15 @@ static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 
 	status = -ENODEV;
 
+	/*
+	 * Reset wMaxPacketSize with maximum packet size of FS bulk transfer before
+	 * endpoint claim. This ensures that the wMaxPacketSize does not exceed the
+	 * limit during bind retries where configured TX/RX FIFO's maxpacket size
+	 * of 512 bytes for IN/OUT endpoints in support HS speed only.
+	 */
+	bulk_in_desc.wMaxPacketSize = cpu_to_le16(64);
+	bulk_out_desc.wMaxPacketSize = cpu_to_le16(64);
+
 	/* allocate instance-specific endpoints */
 	midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
 	if (!midi->in_ep)
-- 
2.17.1