From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from svenfoo.org ([82.94.215.22]:33793 "EHLO mail.zonque.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751758AbbG0INw (ORCPT ); Mon, 27 Jul 2015 04:13:52 -0400 Subject: Re: [PATCH 2/2] usb: gadget: f_uac2: fix calculation of uac2->p_interval To: Peter Chen , balbi@ti.com References: <1437979907-29976-1-git-send-email-peter.chen@freescale.com> <1437979907-29976-2-git-send-email-peter.chen@freescale.com> Cc: linux-usb@vger.kernel.org, stable@vger.kernel.org From: Daniel Mack Message-ID: <55B5E83D.8030709@zonque.org> Date: Mon, 27 Jul 2015 10:13:49 +0200 MIME-Version: 1.0 In-Reply-To: <1437979907-29976-2-git-send-email-peter.chen@freescale.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 07/27/2015 08:51 AM, Peter Chen wrote: > The p_interval should be less if the 'bInterval' at the descriptor > is larger, eg, if 'bInterval' is 5 for HS, the p_interval should be > 8000 / 16 = 500. > > It fixes the patch 9bb87f16 "usb: gadget: f_uac2: send reasonably > sized packets" > Acked-by: Daniel Mack Thanks for spotting this! Daniel > Cc: Daniel Mack > Cc: #v3.18+ > Signed-off-by: Peter Chen > --- > drivers/usb/gadget/function/f_uac2.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c > index 51ca32d..4bd9a8e 100644 > --- a/drivers/usb/gadget/function/f_uac2.c > +++ b/drivers/usb/gadget/function/f_uac2.c > @@ -1191,14 +1191,14 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt) > factor = 1000; > } else { > ep_desc = &hs_epin_desc; > - factor = 125; > + factor = 8000; > } > > /* pre-compute some values for iso_complete() */ > uac2->p_framesize = opts->p_ssize * > num_channels(opts->p_chmask); > rate = opts->p_srate * uac2->p_framesize; > - uac2->p_interval = (1 << (ep_desc->bInterval - 1)) * factor; > + uac2->p_interval = factor / (1 << (ep_desc->bInterval - 1)); > uac2->p_pktsize = min_t(unsigned int, rate / uac2->p_interval, > prm->max_psize); > >