[PATCH] usb:gadget: f_uac1: fixed sync playback

[PATCH] usb:gadget: f_uac1: fixed sync playback

[Pavel Hofman]

The u_audio param fb_max was not set to its default value in f_uac1.c.
As a result the maximum value of Playback Pitch ctl was kept at 1000000,
not allowing to set faster playback pitch for UAC1.

The setting required moving the default constant UAC2_DEF_FB_MAX from
u_uac2.h to FBACK_FAST_MAX in u_audio.h as that header is common for
f_uac1.c and f_uac2.c.

Fixes: 6fec018 ("usb: gadget: u_audio.c: Adding Playback Pitch ctl for
                 sync playback")
Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
---

Notes:
    * for usb-next

 drivers/usb/gadget/function/f_uac1.c  |  1 +
 drivers/usb/gadget/function/f_uac2.c  |  3 ++-
 drivers/usb/gadget/function/u_audio.h | 10 ++++++++--
 drivers/usb/gadget/function/u_uac2.h  |  1 -
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
index 5b3502df4e13..03f50643fbba 100644
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -1321,6 +1321,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 		audio->params.c_fu.volume_res = audio_opts->c_volume_res;
 	}
 	audio->params.req_number = audio_opts->req_number;
+	audio->params.fb_max = FBACK_FAST_MAX;
 	if (FUOUT_EN(audio_opts) || FUIN_EN(audio_opts))
 		audio->notify = audio_notify;
 
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index a5eedd88eee6..74d8b30ca176 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 
 #include "u_audio.h"
+
 #include "u_uac2.h"
 
 /* UAC2 spec: 4.1 Audio Channel Cluster Descriptor */
@@ -1936,7 +1937,7 @@ static struct usb_function_instance *afunc_alloc_inst(void)
 	opts->c_volume_res = UAC2_DEF_RES_DB;
 
 	opts->req_number = UAC2_DEF_REQ_NUM;
-	opts->fb_max = UAC2_DEF_FB_MAX;
+	opts->fb_max = FBACK_FAST_MAX;
 	return &opts->func_inst;
 }
 
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
index 001a79a46022..8dfdae1721cd 100644
--- a/drivers/usb/gadget/function/u_audio.h
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -14,11 +14,17 @@
 /*
  * Same maximum frequency deviation on the slower side as in
  * sound/usb/endpoint.c. Value is expressed in per-mil deviation.
- * The maximum deviation on the faster side will be provided as
- * parameter, as it impacts the endpoint required bandwidth.
  */
 #define FBACK_SLOW_MAX	250
 
+/*
+ * Maximum frequency deviation on the faster side, default value for UAC1/2.
+ * Value is expressed in per-mil deviation.
+ * UAC2 provides the value as a parameter as it impacts the endpoint required
+ * bandwidth.
+ */
+#define FBACK_FAST_MAX 5
+
 /* Feature Unit parameters */
 struct uac_fu_params {
 	int id;			/* Feature Unit ID */
diff --git a/drivers/usb/gadget/function/u_uac2.h b/drivers/usb/gadget/function/u_uac2.h
index a73b35774c44..e0c8e3513bfd 100644
--- a/drivers/usb/gadget/function/u_uac2.h
+++ b/drivers/usb/gadget/function/u_uac2.h
@@ -30,7 +30,6 @@
 #define UAC2_DEF_RES_DB		(1*256)		/* 1 dB */
 
 #define UAC2_DEF_REQ_NUM 2
-#define UAC2_DEF_FB_MAX 5
 #define UAC2_DEF_INT_REQ_NUM	10
 
 struct f_uac2_opts {
-- 
2.25.1

Re: [PATCH] usb:gadget: f_uac1: fixed sync playback

[Greg Kroah-Hartman]

On Fri, Oct 22, 2021 at 04:03:39PM +0200, Pavel Hofman wrote:
> The u_audio param fb_max was not set to its default value in f_uac1.c.
> As a result the maximum value of Playback Pitch ctl was kept at 1000000,
> not allowing to set faster playback pitch for UAC1.
> 
> The setting required moving the default constant UAC2_DEF_FB_MAX from
> u_uac2.h to FBACK_FAST_MAX in u_audio.h as that header is common for
> f_uac1.c and f_uac2.c.
> 
> Fixes: 6fec018 ("usb: gadget: u_audio.c: Adding Playback Pitch ctl for
>                  sync playback")

Nit, in the future the format for this is:

Fixes: 6fec018a7e70 ("usb: gadget: u_audio.c: Adding Playback Pitch ctl for sync playback")

The kernel documentation about submitting patches should describe this.

I'll go hand-edit it, no worries this time.

thanks,

greg k-h