[PATCH stable-5.14 1/2] usb: gadget: f_uac2: Add missing companion descriptor for feedback EP

[PATCH stable-5.14 1/2] usb: gadget: f_uac2: Add missing companion descriptor for feedback EP

[Jack Pham]

commit 595091a1426a3b2625dad322f69fe569dc9d8943 upstream.

The f_uac2 function fails to enumerate when connected in SuperSpeed
due to the feedback endpoint missing the companion descriptor.
Add a new ss_epin_fback_desc_comp descriptor and append it behind the
ss_epin_fback_desc both in the static definition of the ss_audio_desc
structure as well as its dynamic construction in setup_headers().

Fixes: 24f779dac8f3 ("usb: gadget: f_uac2/u_audio: add feedback endpoint support")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Link: https://lore.kernel.org/r/20210909174811.12534-2-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[jackp: Backport to 5.14 with minor conflict resolution]
Signed-off-by: Jack Pham <jackp@codeaurora.org>
---
 drivers/usb/gadget/function/f_uac2.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index ae29ff2b2b68..0bc3e68cae31 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -348,6 +348,14 @@ static struct usb_endpoint_descriptor ss_epin_fback_desc = {
 	.bInterval = 4,
 };
 
+static struct usb_ss_ep_comp_descriptor ss_epin_fback_desc_comp = {
+	.bLength		= sizeof(ss_epin_fback_desc_comp),
+	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
+	.bMaxBurst		= 0,
+	.bmAttributes		= 0,
+	.wBytesPerInterval	= cpu_to_le16(4),
+};
+
 
 /* Audio Streaming IN Interface - Alt0 */
 static struct usb_interface_descriptor std_as_in_if0_desc = {
@@ -527,6 +535,7 @@ static struct usb_descriptor_header *ss_audio_desc[] = {
 	(struct usb_descriptor_header *)&ss_epout_desc_comp,
 	(struct usb_descriptor_header *)&as_iso_out_desc,
 	(struct usb_descriptor_header *)&ss_epin_fback_desc,
+	(struct usb_descriptor_header *)&ss_epin_fback_desc_comp,
 
 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
@@ -604,6 +613,7 @@ static void setup_headers(struct f_uac2_opts *opts,
 {
 	struct usb_ss_ep_comp_descriptor *epout_desc_comp = NULL;
 	struct usb_ss_ep_comp_descriptor *epin_desc_comp = NULL;
+	struct usb_ss_ep_comp_descriptor *epin_fback_desc_comp = NULL;
 	struct usb_endpoint_descriptor *epout_desc;
 	struct usb_endpoint_descriptor *epin_desc;
 	struct usb_endpoint_descriptor *epin_fback_desc;
@@ -626,6 +636,7 @@ static void setup_headers(struct f_uac2_opts *opts,
 		epout_desc_comp = &ss_epout_desc_comp;
 		epin_desc_comp = &ss_epin_desc_comp;
 		epin_fback_desc = &ss_epin_fback_desc;
+		epin_fback_desc_comp = &ss_epin_fback_desc_comp;
 	}
 
 	i = 0;
@@ -654,8 +665,11 @@ static void setup_headers(struct f_uac2_opts *opts,
 
 		headers[i++] = USBDHDR(&as_iso_out_desc);
 
-		if (EPOUT_FBACK_IN_EN(opts))
+		if (EPOUT_FBACK_IN_EN(opts)) {
 			headers[i++] = USBDHDR(epin_fback_desc);
+			if (epin_fback_desc_comp)
+				headers[i++] = USBDHDR(epin_fback_desc_comp);
+		}
 	}
 	if (EPIN_EN(opts)) {
 		headers[i++] = USBDHDR(&std_as_in_if0_desc);
-- 
2.24.0

[PATCH stable-5.14 2/2] usb: gadget: f_uac2: Populate SS descriptors' wBytesPerInterval

[Jack Pham]

commit f0e8a206a2a53a919e1709c654cb65d519f7befb upstream.

For Isochronous endpoints, the SS companion descriptor's
wBytesPerInterval field is required to reserve bus time in order
to transmit the required payload during the service interval.
If left at 0, the UAC2 function is unable to transact data on its
playback or capture endpoints in SuperSpeed mode.

Since f_uac2 currently does not support any bursting this value can
be exactly equal to the calculated wMaxPacketSize.

Tested with Windows 10 as a host.

Fixes: f8cb3d556be3 ("usb: f_uac2: adds support for SS and SSP")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Link: https://lore.kernel.org/r/20210909174811.12534-3-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[jackp: Backport to 5.14 with minor conflict resolution]
Signed-off-by: Jack Pham <jackp@codeaurora.org>
---
 drivers/usb/gadget/function/f_uac2.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 0bc3e68cae31..37c94031af1e 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -951,6 +951,9 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
 	agdev->out_ep_maxpsize = max_t(u16, agdev->out_ep_maxpsize,
 				le16_to_cpu(ss_epout_desc.wMaxPacketSize));
 
+	ss_epin_desc_comp.wBytesPerInterval = ss_epin_desc.wMaxPacketSize;
+	ss_epout_desc_comp.wBytesPerInterval = ss_epout_desc.wMaxPacketSize;
+
 	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
 	hs_epin_fback_desc.bEndpointAddress = fs_epin_fback_desc.bEndpointAddress;
 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
-- 
2.24.0

Re: [PATCH stable-5.14 2/2] usb: gadget: f_uac2: Populate SS descriptors' wBytesPerInterval

[Greg Kroah-Hartman]

On Mon, Sep 27, 2021 at 09:12:53AM -0700, Jack Pham wrote:
> commit f0e8a206a2a53a919e1709c654cb65d519f7befb upstream.
> 
> For Isochronous endpoints, the SS companion descriptor's
> wBytesPerInterval field is required to reserve bus time in order
> to transmit the required payload during the service interval.
> If left at 0, the UAC2 function is unable to transact data on its
> playback or capture endpoints in SuperSpeed mode.
> 
> Since f_uac2 currently does not support any bursting this value can
> be exactly equal to the calculated wMaxPacketSize.
> 
> Tested with Windows 10 as a host.
> 
> Fixes: f8cb3d556be3 ("usb: f_uac2: adds support for SS and SSP")
> Cc: stable <stable@vger.kernel.org>
> Signed-off-by: Jack Pham <jackp@codeaurora.org>
> Link: https://lore.kernel.org/r/20210909174811.12534-3-jackp@codeaurora.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> [jackp: Backport to 5.14 with minor conflict resolution]

Both now queued up, thanks.

greg k-h