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Date:   Thu, 29 Dec 2022 04:31:37 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Ricardo Ribalda <ribalda@chromium.org>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org
Subject: Re: [PATCH RESEND v2 2/2] media: uvcvideo: Limit power line control
 for Lenovo Integrated Camera
Message-ID: <Y6z8Cc9LWa3Nyin3@pendragon.ideasonboard.com>
References: <20221101-easycam-v2-0-ffe3e3a152df@chromium.org>
 <20221101-easycam-v2-2-ffe3e3a152df@chromium.org>
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In-Reply-To: <20221101-easycam-v2-2-ffe3e3a152df@chromium.org>
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Hi Ricardo,

Thank you for the patch.

On Fri, Dec 02, 2022 at 05:45:07PM +0100, Ricardo Ribalda wrote:
> The device does not implement the power line control correctly. Add a
> corresponding control mapping override.

Do I understand correctly that this device advertises UVC 1.5 support
buth implements the power line frequency control as if it was a UVC 1.1
device ? Could you record this in the commit message ?

I wonder how all these cameras can pass the UVC conformance test suite.
Either they don't even bother trying, or the test suite is useless.

> Bus 003 Device 002: ID 30c9:0093 Lenovo Integrated Camera
> Device Descriptor:
>   bLength                18
>   bDescriptorType         1
>   bcdUSB               2.01
>   bDeviceClass          239 Miscellaneous Device
>   bDeviceSubClass         2
>   bDeviceProtocol         1 Interface Association
>   bMaxPacketSize0        64
>   idVendor           0x30c9
>   idProduct          0x0093
>   bcdDevice            0.07
>   iManufacturer           3 Lenovo
>   iProduct                1 Integrated Camera
>   iSerial                 2 8SSC21J75356V1SR2830069
>   bNumConfigurations      1
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_driver.c | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index cca3012c8912..e0bb21f2e133 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -2373,6 +2373,30 @@ MODULE_PARM_DESC(timeout, "Streaming control requests timeout");
>   * Driver initialization and cleanup
>   */
>  
> +static const struct uvc_menu_info power_line_frequency_controls_uvc11[] = {
> +	{ 0, "Disabled" },
> +	{ 1, "50 Hz" },
> +	{ 2, "60 Hz" },
> +};
> +
> +static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_uvc11 = {
> +	.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_uvc11,
> +	.menu_count	= ARRAY_SIZE(power_line_frequency_controls_uvc11),
> +};

It would be nice to avoid duplicating the data, do you think we could
reference uvc_ctrl_mappings_uvc11 from uvc_ctrl.c instead ?

> +
> +static const struct uvc_device_info uvc_ctrl_power_line_uvc11 = {
> +	.mappings = (const struct uvc_control_mapping *[]) {
> +		&uvc_ctrl_power_line_mapping_uvc11,
> +		NULL, /* Sentinel */
> +	},
> +};
>  static const struct uvc_menu_info power_line_frequency_controls_limited[] = {
>  	{ 1, "50 Hz" },
>  	{ 2, "60 Hz" },
> @@ -2976,6 +3000,15 @@ static const struct usb_device_id uvc_ids[] = {
>  	  .bInterfaceSubClass	= 1,
>  	  .bInterfaceProtocol	= 0,
>  	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_FORCE_BPP) },
> +	/* Lenovo Integrated Camera */
> +	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
> +				| USB_DEVICE_ID_MATCH_INT_INFO,
> +	  .idVendor		= 0x30c9,
> +	  .idProduct		= 0x0093,
> +	  .bInterfaceClass	= USB_CLASS_VIDEO,
> +	  .bInterfaceSubClass	= 1,
> +	  .bInterfaceProtocol	= UVC_PC_PROTOCOL_15,
> +	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_uvc11 },
>  	/* Sonix Technology USB 2.0 Camera */
>  	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
>  				| USB_DEVICE_ID_MATCH_INT_INFO,

-- 
Regards,

Laurent Pinchart