Hi,
tom.leiming@xxxxxxxxx wrote:
> From: Ming Lei <tom.leiming@xxxxxxxxx>
>
> This patch introduces isochronous source sink function driver
> into zero composite driver. The driver is based on David Brownell's
> f_sourcesink.c
>
> +/*-------------------------------------------------------------------------*/
> +static int __init
> +iso_sourcesink_bind(struct usb_configuration *c, struct usb_function *f)
> + if (gadget_is_dualspeed(c->cdev->gadget))
> + hs = 1;
> + else
> + hs = 0;
> +
> + /*use the ep desc with the strongest capability to configure hw ep*/
> + if (hs) {
> + ialt = ss->hs_alt;
> + max_in = ialt[(int)ss->hs_in_maxp_alt].source_ep_desc;
> + max_out = ialt[(int)ss->hs_out_maxp_alt].sink_ep_desc;
> + } else {
> + ialt = ss->fs_alt;
> + max_in = ialt[(int)ss->fs_in_maxp_alt].source_ep_desc;
> + max_out = ialt[(int)ss->fs_out_maxp_alt].sink_ep_desc;
> + }
> +
>
Have you tested this on dual speed gadget hardware connected to a full
speed only host?
To get that configuration to work for me I had to force hs=0 in the
above code.
Otherwise using a configuration like
fs:alt0:alt1,in/512/1,out/512/1:hs:alt0:alt1,in/1024*3/1:alt2,in/1024/1
(note fs has in and out whereas hs has in only)
causes an oops in enable_iso_source_sink() because one of the endpoints
is null.
The problem seems to be that iso_sourcesink_bind() sets up ss->in_ep and
ss->out_ep based
on the configuration for the gadget hardware regardless of the host
capabilities.
> +static int iso_source_sink_start_ep(struct f_iso_sourcesink *ss, bool is_in)
> +{
> + struct usb_ep *ep;
> + struct usb_request *req;
> + int status;
> +
> + ep = is_in ? ss->in_ep : ss->out_ep;
> + if (ep)
> + return 0;
>
>
Shouldn"t this be
if (!ep)
return 0;
??
Otherwise no requests are actually submitted.
As usbtest #16 doesn't actually check the length
of data transfered the test is still OK but nothing
is transferred...
I also have another "strange" behaviour but that may be due to my
misunderstanding:
When I configure different max packet sizes for IN transfers and observe
the data size
on the bus (with a bus analyser) I see:
config bus
256 256
512 512
248 256
1020 1024
1023 1024
IE there seems to be a round up to next power of two behaviour
(including to 1024
even though the limit for full speed is 1023...)
Regards,
Martin
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