Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933718AbcCIThk (ORCPT ); Wed, 9 Mar 2016 14:37:40 -0500 Received: from mail-wm0-f46.google.com ([74.125.82.46]:35280 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751459AbcCIThb (ORCPT ); Wed, 9 Mar 2016 14:37:31 -0500 From: "Felipe F. Tonello" To: linux-usb@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Felipe Balbi , Michal Nazarewicz , Robert Baldyga Subject: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize Date: Wed, 9 Mar 2016 19:39:30 +0000 Message-Id: <1457552370-29404-1-git-send-email-eu@felipetonello.com> X-Mailer: git-send-email 2.7.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1342 Lines: 42 buflen by default (256) is smaller than wMaxPacketSize (512) in high-speed devices. That caused the OUT endpoint to freeze if the host send any data packet of length greater than 256 bytes. This is an example dump of what happended on that enpoint: HOST: [DATA][Length=260][...] DEVICE: [NAK] HOST: [PING] DEVICE: [NAK] HOST: [PING] DEVICE: [NAK] ... HOST: [PING] DEVICE: [NAK] This patch fixes this problem by setting the minimum usb_request's buffer size for the OUT endpoint as its wMaxPacketSize. Signed-off-by: Felipe F. Tonello --- drivers/usb/gadget/function/f_midi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 8475e3dc82d4..826ba641f29d 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -366,7 +366,9 @@ static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt) /* allocate a bunch of read buffers and queue them all at once. */ for (i = 0; i < midi->qlen && err == 0; i++) { struct usb_request *req = - midi_alloc_ep_req(midi->out_ep, midi->buflen); + midi_alloc_ep_req(midi->out_ep, + max_t(unsigned, midi->buflen, + bulk_out_desc.wMaxPacketSize)); if (req == NULL) return -ENOMEM; -- 2.7.2