* [PATCH v5 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth
@ 2015-07-28 9:17 Peter Chen
2015-07-28 10:38 ` Daniel Mack
0 siblings, 1 reply; 3+ messages in thread
From: Peter Chen @ 2015-07-28 9:17 UTC (permalink / raw)
To: balbi
Cc: linux-usb, Peter Chen, andrzej.p, Daniel Mack, tiwai, stable,
Alan Stern
According to USB Audio Device 2.0 Spec, Ch4.10.1.1:
wMaxPacketSize is defined as follows:
Maximum packet size this endpoint is capable of sending or receiving
when this configuration is selected.
This is determined by the audio bandwidth constraints of the endpoint.
In current code, the wMaxPacketSize is defined as the maximum packet size
for ISO endpoint, and it will let the host reserve much more space than
it really needs, so that we can't let more endpoints work together at
one frame.
We find this issue when we try to let 4 f_uac2 gadgets work together [1]
at FS connection.
[1]http://www.spinics.net/lists/linux-usb/msg123478.html
Cc: andrzej.p@samsung.com
Cc: Daniel Mack <zonque@gmail.com>
Cc: tiwai@suse.de
Cc: <stable@vger.kernel.org> #v3.18+
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
---
Changes for v5:
- Add additional parameters 'is_playback' for helper
- Add const for parameter 'struct f_uac2_opts *uac2_opts'
- Put all three int variables at one line
- Fix the CodeStyle problem
Changes for v4:
- Add helper set_ep_max_packet_size to calculate max packet size
Changes for v3:
- Consider 'bInterval' to calculate wMaxPacketSize
- playback endpoint is IN ep, and capture endpoint is OUT ep
Changes for v2:
- Using DIV_ROUND_UP to calculate max packet size
drivers/usb/gadget/function/f_uac2.c | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 5318615..fa93d79 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -975,6 +975,29 @@ free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep)
"%s:%d Error!\n", __func__, __LINE__);
}
+static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
+ struct usb_endpoint_descriptor *ep_desc,
+ unsigned int factor, bool is_playback)
+{
+ int chmask, srate, ssize;
+ u16 max_packet_size;
+
+ if (is_playback) {
+ chmask = uac2_opts->p_chmask;
+ srate = uac2_opts->p_srate;
+ ssize = uac2_opts->p_ssize;
+ } else {
+ 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 +1093,14 @@ 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, true);
+ set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
+ set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
+ set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
+
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)
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v5 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth
2015-07-28 9:17 [PATCH v5 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth Peter Chen
@ 2015-07-28 10:38 ` Daniel Mack
2015-07-29 1:27 ` Peter Chen
0 siblings, 1 reply; 3+ messages in thread
From: Daniel Mack @ 2015-07-28 10:38 UTC (permalink / raw)
To: Peter Chen, balbi; +Cc: linux-usb, andrzej.p, tiwai, stable, Alan Stern
On 07/28/2015 11:17 AM, Peter Chen wrote:
> According to USB Audio Device 2.0 Spec, Ch4.10.1.1:
> wMaxPacketSize is defined as follows:
> Maximum packet size this endpoint is capable of sending or receiving
> when this configuration is selected.
> This is determined by the audio bandwidth constraints of the endpoint.
>
> In current code, the wMaxPacketSize is defined as the maximum packet size
> for ISO endpoint, and it will let the host reserve much more space than
> it really needs, so that we can't let more endpoints work together at
> one frame.
>
> We find this issue when we try to let 4 f_uac2 gadgets work together [1]
> at FS connection.
>
> [1]http://www.spinics.net/lists/linux-usb/msg123478.html
>
> Cc: andrzej.p@samsung.com
> Cc: Daniel Mack <zonque@gmail.com>
> Cc: tiwai@suse.de
> Cc: <stable@vger.kernel.org> #v3.18+
> Cc: Alan Stern <stern@rowland.harvard.edu>
> Signed-off-by: Peter Chen <peter.chen@freescale.com>
Looks good to me now! I currently don't have hardware to test this on,
though.
Acked-by: Daniel Mack <zonque@gmail.com>
Thanks,
Daniel
> ---
>
> Changes for v5:
> - Add additional parameters 'is_playback' for helper
> - Add const for parameter 'struct f_uac2_opts *uac2_opts'
> - Put all three int variables at one line
> - Fix the CodeStyle problem
>
> Changes for v4:
> - Add helper set_ep_max_packet_size to calculate max packet size
>
> Changes for v3:
> - Consider 'bInterval' to calculate wMaxPacketSize
> - playback endpoint is IN ep, and capture endpoint is OUT ep
>
> Changes for v2:
> - Using DIV_ROUND_UP to calculate max packet size
>
> drivers/usb/gadget/function/f_uac2.c | 31 +++++++++++++++++++++++++++++--
> 1 file changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
> index 5318615..fa93d79 100644
> --- a/drivers/usb/gadget/function/f_uac2.c
> +++ b/drivers/usb/gadget/function/f_uac2.c
> @@ -975,6 +975,29 @@ free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep)
> "%s:%d Error!\n", __func__, __LINE__);
> }
>
> +static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
> + struct usb_endpoint_descriptor *ep_desc,
> + unsigned int factor, bool is_playback)
> +{
> + int chmask, srate, ssize;
> + u16 max_packet_size;
> +
> + if (is_playback) {
> + chmask = uac2_opts->p_chmask;
> + srate = uac2_opts->p_srate;
> + ssize = uac2_opts->p_ssize;
> + } else {
> + 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 +1093,14 @@ 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, true);
> + set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
> + set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
> + set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
> +
> 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)
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: [PATCH v5 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth
2015-07-28 10:38 ` Daniel Mack
@ 2015-07-29 1:27 ` Peter Chen
0 siblings, 0 replies; 3+ messages in thread
From: Peter Chen @ 2015-07-29 1:27 UTC (permalink / raw)
To: Daniel Mack, balbi@ti.com
Cc: linux-usb@vger.kernel.org, andrzej.p@samsung.com, tiwai@suse.de,
stable@vger.kernel.org, Alan Stern
> On 07/28/2015 11:17 AM, Peter Chen wrote:
> > According to USB Audio Device 2.0 Spec, Ch4.10.1.1:
> > wMaxPacketSize is defined as follows:
> > Maximum packet size this endpoint is capable of sending or receiving
> > when this configuration is selected.
> > This is determined by the audio bandwidth constraints of the endpoint.
> >
> > In current code, the wMaxPacketSize is defined as the maximum packet
> > size for ISO endpoint, and it will let the host reserve much more
> > space than it really needs, so that we can't let more endpoints work
> > together at one frame.
> >
> > We find this issue when we try to let 4 f_uac2 gadgets work together
> > [1] at FS connection.
> >
> > [1]http://www.spinics.net/lists/linux-usb/msg123478.html
> >
> > Cc: andrzej.p@samsung.com
> > Cc: Daniel Mack <zonque@gmail.com>
> > Cc: tiwai@suse.de
> > Cc: <stable@vger.kernel.org> #v3.18+
> > Cc: Alan Stern <stern@rowland.harvard.edu>
> > Signed-off-by: Peter Chen <peter.chen@freescale.com>
>
> Looks good to me now! I currently don't have hardware to test this on, though.
>
I have tested it.
Peter
> Acked-by: Daniel Mack <zonque@gmail.com>
>
>
> Thanks,
> Daniel
>
> > ---
> >
> > Changes for v5:
> > - Add additional parameters 'is_playback' for helper
> > - Add const for parameter 'struct f_uac2_opts *uac2_opts'
> > - Put all three int variables at one line
> > - Fix the CodeStyle problem
> >
> > Changes for v4:
> > - Add helper set_ep_max_packet_size to calculate max packet size
> >
> > Changes for v3:
> > - Consider 'bInterval' to calculate wMaxPacketSize
> > - playback endpoint is IN ep, and capture endpoint is OUT ep
> >
> > Changes for v2:
> > - Using DIV_ROUND_UP to calculate max packet size
> >
> > drivers/usb/gadget/function/f_uac2.c | 31
> > +++++++++++++++++++++++++++++--
> > 1 file changed, 29 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/gadget/function/f_uac2.c
> > b/drivers/usb/gadget/function/f_uac2.c
> > index 5318615..fa93d79 100644
> > --- a/drivers/usb/gadget/function/f_uac2.c
> > +++ b/drivers/usb/gadget/function/f_uac2.c
> > @@ -975,6 +975,29 @@ free_ep(struct uac2_rtd_params *prm, struct
> usb_ep *ep)
> > "%s:%d Error!\n", __func__, __LINE__); }
> >
> > +static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
> > + struct usb_endpoint_descriptor *ep_desc,
> > + unsigned int factor, bool is_playback) {
> > + int chmask, srate, ssize;
> > + u16 max_packet_size;
> > +
> > + if (is_playback) {
> > + chmask = uac2_opts->p_chmask;
> > + srate = uac2_opts->p_srate;
> > + ssize = uac2_opts->p_ssize;
> > + } else {
> > + 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 +1093,14 @@ 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, true);
> > + set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
> > + set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
> > + set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
> > +
> > 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)
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-07-28 9:17 [PATCH v5 1/1] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth Peter Chen
2015-07-28 10:38 ` Daniel Mack
2015-07-29 1:27 ` Peter Chen
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