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

Selvarasu Ganesan
2024-12-08T15:28:42Z

Hello Maintainers,

Please ignore this commit as this duplicate copy of
https://lore.kernel.org/linux-usb/20241208152322.1653-1-selvarasu.g@samsung.com/

Thanks,

Selva

On 12/8/2024 8:43 PM, Faraz Ata wrote:
> From: Selvarasu Ganesan <selvarasu.g@samsung.com>
>
> 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@vger.kernel.org
> Signed-off-by: Selvarasu Ganesan <selvarasu.g@samsung.com>
> ---
> 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)