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usb: gadget: f_uac2: Add missing companion descriptor for feedback EP

PATCH In review Jack Pham 2 participants 3 messages Sep 27, 2021 Stable branch

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#1 lore raw

PATCH 2/2 usb: gadget: f_uac2: Populate SS descriptors' wBytesPerInterval

In reply to 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 <[email protected]>
Signed-off-by Jack Pham <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
[jackp: Backport to 5.14 with minor conflict resolution]
Signed-off-by Jack Pham <[email protected]>
---
 drivers/usb/gadget/function/f_uac2.c | 3 +++
 1 file changed, 3 insertions(+)
drivers/usb/gadget/function/f_uac2.c +3 -0
index 0bc3e68cae31..37c94031af1e 100644
@@ -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;
Signature · 1 line
2.24.0

Jack Pham

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#0 lore raw

PATCH 1/2 usb: gadget: f_uac2: Add missing companion descriptor for feedback EP

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 <[email protected]>
Signed-off-by Jack Pham <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
[jackp: Backport to 5.14 with minor conflict resolution]
Signed-off-by Jack Pham <[email protected]>
---
 drivers/usb/gadget/function/f_uac2.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
drivers/usb/gadget/function/f_uac2.c +15 -1
index ae29ff2b2b68..0bc3e68cae31 100644
@@ -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);
Signature · 1 line
2.24.0
maintainer
#2 lore raw

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

In reply to Jack Pham
Quoted 11 lines · 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.

Quoted 8 lines

Tested with Windows 10 as a host.

Fixes f8cb3d556be3 ("usb: f_uac2: adds support for SS and SSP")
Cc stable <[email protected]>
Signed-off-by Jack Pham <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
[jackp: Backport to 5.14 with minor conflict resolution]

Both now queued up, thanks.

greg k-h