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From: Michael Jordan <jordan.mymail@gmail.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hans de Goede <hansg@kernel.org>,
	Ricardo Ribalda <ribalda@chromium.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Hans Verkuil <hverkuil+cisco@kernel.org>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	Michael Jordan <jordan.mymail@gmail.com>
Subject: [PATCH v3 4/4] media: uvcvideo: fix up missing AUTO_UPDATE on the OBSBOT Tail 2
Date: Mon, 28 Sep 2026 11:24:16 -0400	[thread overview]
Message-ID: <20260928152416.766957-5-jordan.mymail@gmail.com> (raw)
In-Reply-To: <20260928152416.766957-1-jordan.mymail@gmail.com>

The OBSBOT Tail 2 (3564:fefc) has the same firmware defect as the
Tiny 2: GET_INFO reports 0x03 (GET and SET, no AUTOUPDATE) for
CT_PANTILT_ABSOLUTE, CT_PANTILT_RELATIVE and CT_ZOOM_ABSOLUTE, so
uvcvideo returns the last value written by the host instead of the
current one.

As on the Tiny 2, the device changes all three controls on its own
(commanded moves, subject tracking, and zoom changed at the camera),
GET_CUR reports the live values, and no control change events are sent
on the interrupt endpoint.

Add fixup entries restoring AUTO_UPDATE for the three controls, with
the same flags as the Tiny 2 entries.

Exposure, white balance and focus are left alone for the same reason
as on the Tiny 2: their GET_CUR does not track the auto mode.

lsusb -v (device descriptor and Camera Terminal):

  Bus 002 Device 003: ID 3564:fefc Remo Tech Co., Ltd. OBSBOT Tail 2
  Device Descriptor:
    bLength                18
    bDescriptorType         1
    bcdUSB               3.20
    bDeviceClass          239 Miscellaneous Device
    bDeviceSubClass         2 [unknown]
    bDeviceProtocol         1 Interface Association
    bMaxPacketSize0         9
    idVendor           0x3564 Remo Tech Co., Ltd.
    idProduct          0xfefc OBSBOT Tail 2
    bcdDevice            4.19
    iManufacturer           1 Remo Tech Co., Ltd.
    iProduct                2 OBSBOT Tail 2
    iSerial                 0
    bNumConfigurations      1
  [...]
      VideoControl Interface Descriptor:
        bLength                18
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             1
        wTerminalType      0x0201 Camera Sensor
        bAssocTerminal          0
        iTerminal               0
        wObjectiveFocalLengthMin      0
        wObjectiveFocalLengthMax      0
        wOcularFocalLength            0
        bControlSize                  3
        bmControls           0x00023e3e
          Auto-Exposure Mode
          Auto-Exposure Priority
          Exposure Time (Absolute)
          Exposure Time (Relative)
          Focus (Absolute)
          Zoom (Absolute)
          Zoom (Relative)
          PanTilt (Absolute)
          PanTilt (Relative)
          Roll (Absolute)
          Focus, Auto

Assisted-by: Claude:claude-fable-5
Signed-off-by: Michael Jordan <jordan.mymail@gmail.com>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 49ea6a6bcf57..202c2c95432a 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2888,6 +2888,18 @@ static bool uvc_ctrl_fixup_flags(struct uvc_device *dev,
 			UVC_CT_ZOOM_ABSOLUTE_CONTROL,
 			UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_RANGE |
 			UVC_CTRL_FLAG_RESTORE | UVC_CTRL_FLAG_AUTO_UPDATE },
+		{ { USB_DEVICE(0x3564, 0xfefc) }, 1,
+			UVC_CT_PANTILT_ABSOLUTE_CONTROL,
+			UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_RANGE |
+			UVC_CTRL_FLAG_RESTORE | UVC_CTRL_FLAG_AUTO_UPDATE },
+		{ { USB_DEVICE(0x3564, 0xfefc) }, 1,
+			UVC_CT_PANTILT_RELATIVE_CONTROL,
+			UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_RANGE |
+			UVC_CTRL_FLAG_AUTO_UPDATE },
+		{ { USB_DEVICE(0x3564, 0xfefc) }, 1,
+			UVC_CT_ZOOM_ABSOLUTE_CONTROL,
+			UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_RANGE |
+			UVC_CTRL_FLAG_RESTORE | UVC_CTRL_FLAG_AUTO_UPDATE },
 	};
 
 	unsigned int i;
-- 
2.43.0


      parent reply	other threads:[~2026-09-28 15:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-28 15:24 [PATCH v3 0/4] media: uvcvideo: live pan/tilt/zoom readback on OBSBOT Tiny 2 and " Michael Jordan
2026-09-28 15:24 ` [PATCH v3 1/4] media: uvcvideo: report AUTO_UPDATE controls as volatile Michael Jordan
2026-09-28 15:24 ` [PATCH v3 2/4] media: uvcvideo: generalise the XU flags fixup to all controls Michael Jordan
2026-09-28 17:50   ` Ricardo Ribalda
2026-09-28 18:02     ` Michael Jordan
2026-09-28 15:24 ` [PATCH v3 3/4] media: uvcvideo: fix up missing AUTO_UPDATE on the OBSBOT Tiny 2 Michael Jordan
2026-09-28 15:24 ` Michael Jordan [this message]

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