Re: [PATCH v4 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth

[Peter Chen <peter.chen@freescale.com>]

On Tue, Jul 28, 2015 at 10:13:48AM +0200, Daniel Mack wrote:
> 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.

oh, I forget to run it when send this version.

> 
> > +{
> > +	int chmask;
> > +	int srate;
> > +	int ssize;
> 
> These can be put in one line.
> 

I will change it

> > +	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.

I will change it, thanks.

> 
> 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)
> > 
> 

-- 

Best Regards,
Peter Chen