Re: [PATCH v7 4/8] media: uvcvideo: Limit power line control for Quanta UVC Webcam

From: Laurent Pinchart
Date: Fri Jun 17 2022 - 10:02:13 EST


Hi Ricardo,

Thank you for the patch.

On Fri, Jun 17, 2022 at 12:36:41PM +0200, Ricardo Ribalda wrote:
> The device does not implement the power line control correctly. Add a
> corresponding control mapping override.
>
> Bus 001 Device 003: ID 0408:3090 Quanta Computer, Inc. USB2.0 HD UVC WebCam
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 239 Miscellaneous Device
> bDeviceSubClass 2
> bDeviceProtocol 1 Interface Association
> bMaxPacketSize0 64
> idVendor 0x0408 Quanta Computer, Inc.
> idProduct 0x3090
> bcdDevice 0.04
> iManufacturer 3 Quanta
> iProduct 1 USB2.0 HD UVC WebCam
> iSerial 2 0x0001
> bNumConfigurations 1
>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_driver.c | 35 ++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index 6c86faecbea2..4fb07084f1c0 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -2643,6 +2643,32 @@ MODULE_PARM_DESC(timeout, "Streaming control requests timeout");
> * Driver initialization and cleanup
> */
>
> +static const struct uvc_menu_info power_line_frequency_controls_limited[] = {
> + { 0, "Invalid" },
> + { 1, "50 Hz" },
> + { 2, "60 Hz" },
> +};

It's not nice to have to include the first item in the array, but we
can't fix that without modifying uvc_menu_info, which we can't do as
it's part of the UAPI. Let's keep it as-is, but I would then expose the
uvc_menu_info array from uvc_ctrl.c instead of duplicating it here.

> +
> +static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_limited = {
> + .id = V4L2_CID_POWER_LINE_FREQUENCY,
> + .entity = UVC_GUID_UVC_PROCESSING,
> + .selector = UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
> + .size = 2,
> + .offset = 0,
> + .v4l2_type = V4L2_CTRL_TYPE_MENU,
> + .data_type = UVC_CTRL_DATA_TYPE_ENUM,
> + .menu_info = power_line_frequency_controls_limited,
> + .menu_min = 1,
> + .menu_count = ARRAY_SIZE(power_line_frequency_controls_limited),
> +};
> +
> +static const struct uvc_device_info uvc_ctrl_power_line_limited = {
> + .mappings = (const struct uvc_control_mapping *[]) {
> + &uvc_ctrl_power_line_mapping_limited,
> + NULL, /* Sentinel */
> + },
> +};
> +
> static const struct uvc_device_info uvc_quirk_probe_minmax = {
> .quirks = UVC_QUIRK_PROBE_MINMAX,
> };
> @@ -2673,6 +2699,15 @@ static const struct uvc_device_info uvc_quirk_force_y8 = {
> * though they are compliant.
> */
> static const struct usb_device_id uvc_ids[] = {
> + /* Quanta USB2.0 HD UVC Webcam */
> + { .match_flags = USB_DEVICE_ID_MATCH_DEVICE
> + | USB_DEVICE_ID_MATCH_INT_INFO,
> + .idVendor = 0x0408,
> + .idProduct = 0x3090,
> + .bInterfaceClass = USB_CLASS_VIDEO,
> + .bInterfaceSubClass = 1,
> + .bInterfaceProtocol = 0,
> + .driver_info = (kernel_ulong_t)&uvc_ctrl_power_line_limited },
> /* LogiLink Wireless Webcam */
> { .match_flags = USB_DEVICE_ID_MATCH_DEVICE
> | USB_DEVICE_ID_MATCH_INT_INFO,

--
Regards,

Laurent Pinchart