Re: [RFC][PATCH] usb: gadget: rndis: Free the response queue during REMOTE_NDIS_RESET_MSG

[Amit Pundir]

Please ignore this one. I build tested these patches in series and
turned out it can't be build independently because configNr is
deprecated. I'll resend this patch.

Nevertheless I'd like to get a feedback on the real problem this patch
is trying to solve here.

Thanks,
Amit Pundir

On 9 February 2016 at 01:37, Amit Pundir <amit.pundir@xxxxxxxxxx> wrote:
> From: xerox_lin <xerox_lin@xxxxxxx>
>
> When rndis data transfer is in progress, some Windows7 Host PC is not
> sending the GET_ENCAPSULATED_RESPONSE command for receiving the response
> for the previous SEND_ENCAPSULATED_COMMAND processed.
>
> The rndis function driver appends each response for the
> SEND_ENCAPSULATED_COMMAND in a queue. As the above process got corrupted,
> the Host sends a REMOTE_NDIS_RESET_MSG command to do a soft-reset.
> As the rndis response queue is not freed, the previous response is sent
> as a part of this REMOTE_NDIS_RESET_MSG's reset response and the Host
> blocks any more Rndis transfers.
>
> Hence free the rndis response queue as a part of this soft-reset so that
> the current response for REMOTE_NDIS_RESET_MSG is sent properly during the
> response command.
>
> Cc: Felipe Balbi <balbi@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
> Cc: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx>
> Cc: John Stultz <john.stultz@xxxxxxxxxx>
> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
> Signed-off-by: Rajkumar Raghupathy <raghup@xxxxxxxxxxxxxx>
> Signed-off-by: Xerox Lin <xerox_lin@xxxxxxx>
> [pundir: cherry-picked this patch from AOSP experimental/android-4.4 tree.]
> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
> ---
> Cherry-picked this patch from AOSP common/experimental/android-4.4 tree.
> I could not find upstream submission history for this patch, so my
> apologies in advance if this has already been NACKed before.
>
>  drivers/usb/gadget/function/rndis.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
> index 70d3917..27163e8 100644
> --- a/drivers/usb/gadget/function/rndis.c
> +++ b/drivers/usb/gadget/function/rndis.c
> @@ -681,6 +681,13 @@ static int rndis_reset_response(struct rndis_params *params,
>         rndis_reset_cmplt_type *resp;
>         rndis_resp_t *r;
>
> +       u32 length;
> +       u8 *xbuf;
> +
> +       /* drain the response queue */
> +       while ((xbuf = rndis_get_next_response(configNr, &length)))
> +               rndis_free_response(configNr, xbuf);
> +
>         r = rndis_add_response(params, sizeof(rndis_reset_cmplt_type));
>         if (!r)
>                 return -ENOMEM;
> --
> 1.9.1
>