[PATCH] sound: usb: remove Wireless USB dead code

[PATCH] sound: usb: remove Wireless USB dead code

[Ruslan Bilovol]

Wireless USB host controller support has been removed
from Linux Kernel more than 3 years ago in commit
caa6772db4c1 ("Staging: remove wusbcore and UWB from the
kernel tree."), and the associated code in the
snd-usb-audio driver became unused and untested.

If in the future somebody will return WUSB/UWB support
back to the kernel, the snd-usb-audio driver will reject
Wireless USB audio devices at probe stage, and this patch
should be reverted.

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
---
 sound/usb/card.c     |  1 -
 sound/usb/endpoint.c | 16 +---------------
 sound/usb/helper.c   |  1 -
 3 files changed, 1 insertion(+), 17 deletions(-)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 26268ffb8274..f6e99ced8068 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -609,7 +609,6 @@ static int snd_usb_audio_create(struct usb_interface *intf,
 	case USB_SPEED_LOW:
 	case USB_SPEED_FULL:
 	case USB_SPEED_HIGH:
-	case USB_SPEED_WIRELESS:
 	case USB_SPEED_SUPER:
 	case USB_SPEED_SUPER_PLUS:
 		break;
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 419302e2057e..1e0af1179ca8 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1173,22 +1173,8 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep)
 	 */
 	if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {
 
-		urb_packs = packs_per_ms;
-		/*
-		 * Wireless devices can poll at a max rate of once per 4ms.
-		 * For dataintervals less than 5, increase the packet count to
-		 * allow the host controller to use bursting to fill in the
-		 * gaps.
-		 */
-		if (snd_usb_get_speed(chip->dev) == USB_SPEED_WIRELESS) {
-			int interval = ep->datainterval;
-			while (interval < 5) {
-				urb_packs <<= 1;
-				++interval;
-			}
-		}
 		/* make capture URBs <= 1 ms and smaller than a period */
-		urb_packs = min(max_packs_per_urb, urb_packs);
+		urb_packs = min(max_packs_per_urb, packs_per_ms);
 		while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)
 			urb_packs >>= 1;
 		ep->nurbs = MAX_URBS;
diff --git a/sound/usb/helper.c b/sound/usb/helper.c
index a4410267bf70..bf80e55d013a 100644
--- a/sound/usb/helper.c
+++ b/sound/usb/helper.c
@@ -108,7 +108,6 @@ unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
 {
 	switch (snd_usb_get_speed(chip->dev)) {
 	case USB_SPEED_HIGH:
-	case USB_SPEED_WIRELESS:
 	case USB_SPEED_SUPER:
 	case USB_SPEED_SUPER_PLUS:
 		if (get_endpoint(alts, 0)->bInterval >= 1 &&
-- 
2.39.2

Re: [PATCH] sound: usb: remove Wireless USB dead code

[Takashi Iwai]

On Sun, 12 Mar 2023 23:28:57 +0100,
Ruslan Bilovol wrote:
> 
> Wireless USB host controller support has been removed
> from Linux Kernel more than 3 years ago in commit
> caa6772db4c1 ("Staging: remove wusbcore and UWB from the
> kernel tree."), and the associated code in the
> snd-usb-audio driver became unused and untested.
> 
> If in the future somebody will return WUSB/UWB support
> back to the kernel, the snd-usb-audio driver will reject
> Wireless USB audio devices at probe stage, and this patch
> should be reverted.
> 
> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>

Thanks, applied now to for-next branch.


Takashi