From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from svenfoo.org ([82.94.215.22]:53045 "EHLO mail.zonque.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883AbbG1INv (ORCPT ); Tue, 28 Jul 2015 04:13:51 -0400 Subject: Re: [PATCH v4 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth To: Peter Chen , balbi@ti.com References: <1438047504-19786-1-git-send-email-peter.chen@freescale.com> Cc: linux-usb@vger.kernel.org, andrzej.p@samsung.com, tiwai@suse.de, stable@vger.kernel.org, Alan Stern From: Daniel Mack Message-ID: <55B739BC.7010700@zonque.org> Date: Tue, 28 Jul 2015 10:13:48 +0200 MIME-Version: 1.0 In-Reply-To: <1438047504-19786-1-git-send-email-peter.chen@freescale.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: On 07/28/2015 03:38 AM, Peter Chen wrote: > diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c > index 5318615..6a8e0d2 100644 > --- a/drivers/usb/gadget/function/f_uac2.c > +++ b/drivers/usb/gadget/function/f_uac2.c > @@ -975,6 +975,31 @@ free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep) > "%s:%d Error!\n", __func__, __LINE__); > } > > +static void set_ep_max_packet_size (struct f_uac2_opts *uac2_opts, > + struct usb_endpoint_descriptor *ep_desc, unsigned int factor) scripts/checkpatch.pl will complain about a stray space before '(' and wrong indentation. Also, uac2_opts can be const. > +{ > + int chmask; > + int srate; > + int ssize; These can be put in one line. > + u16 max_packet_size; > + > + if (ep_desc == &fs_epin_desc || ep_desc == &hs_epin_desc) { > + chmask = uac2_opts->p_chmask; > + srate = uac2_opts->p_srate; > + ssize = uac2_opts->p_ssize; > + } else { > + WARN_ON (ep_desc != &fs_epout_desc && ep_desc != &hs_epout_desc); I would rather pass a boolean flag called 'is_playback' than checking the input parameter like this. But I forgot this detail in my proposal, I admit. Apart from that, I like the patch. Thanks, Daniel > + chmask = uac2_opts->c_chmask; > + srate = uac2_opts->c_srate; > + ssize = uac2_opts->c_ssize; > + } > + > + max_packet_size = num_channels(chmask) * ssize * > + DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1))); > + ep_desc->wMaxPacketSize = min(cpu_to_le16(max_packet_size), > + ep_desc->wMaxPacketSize); > +} > + > static int > afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) > { > @@ -1070,10 +1095,14 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) > uac2->p_prm.uac2 = uac2; > uac2->c_prm.uac2 = uac2; > > + /* Calculate wMaxPacketSize according to audio bandwidth */ > + set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000); > + set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000); > + set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000); > + set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000); > + > hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress; > - hs_epout_desc.wMaxPacketSize = fs_epout_desc.wMaxPacketSize; > hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress; > - hs_epin_desc.wMaxPacketSize = fs_epin_desc.wMaxPacketSize; > > ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL); > if (ret) >