linux-kernel - Re: [PATCH v2] media: cx18: Remove unused cx18_reset_ir

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Message-ID: <Zx_s76gUaQwAxzip@gofer.mess.org>
Date: Mon, 28 Oct 2024 19:58:39 +0000
From: Sean Young <sean@...s.org>
To: linux@...blig.org
Cc: awalls@...metrocast.net, mchehab@...nel.org,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] media: cx18: Remove unused cx18_reset_ir_gpio

On Sun, Oct 13, 2024 at 12:39:32AM +0100, linux@...blig.org wrote:
> From: "Dr. David Alan Gilbert" <linux@...blig.org>
> 
> cx18_reset_ir_gpio() has been unused in tree since 2009
> commit eefe1010a465 ("V4L/DVB (10759): cx18: Convert GPIO connected
> functions to act as v4l2_subdevices")
> 
> It has a comment saying it's exported for use by 'lirc_pvr150' but I don't
> see any sign of it in the lirc git, and I see it removed support
> for lirc_i2c.c 'Flavors of the Hauppage PVR-150...' in 2014.
> 
> Remove it.

Interesting, I can't find any call site either. The ir-i2c-kbd driver could
potentially use this, but it would to know the correct v4l2_dev for the
device; also there are devices other than the cx18 which use the same IR
module, so they would not have a way to force a reset or need a different
mechanism (e.g. ivtv driver).

So I don't understand how this could be wired up or how it was ever wired
up.

This could be great because if done correctly, we could remove the
VIDIOC_INT_RESET ioctl completely. Then again, I don't know how often the
device hangs. With the current driver the IR module I don't know of any
hangs -- maybe the ioctl could just go anyway.


Sean

> 
> Signed-off-by: Dr. David Alan Gilbert <linux@...blig.org>
> ---
>  drivers/media/pci/cx18/cx18-gpio.c | 15 ---------------
>  drivers/media/pci/cx18/cx18-gpio.h |  1 -
>  2 files changed, 16 deletions(-)
> 
> diff --git a/drivers/media/pci/cx18/cx18-gpio.c b/drivers/media/pci/cx18/cx18-gpio.c
> index c85eb8d25837..485a6cbeb15a 100644
> --- a/drivers/media/pci/cx18/cx18-gpio.c
> +++ b/drivers/media/pci/cx18/cx18-gpio.c
> @@ -305,21 +305,6 @@ int cx18_gpio_register(struct cx18 *cx, u32 hw)
>  	return v4l2_device_register_subdev(&cx->v4l2_dev, sd);
>  }
>  
> -void cx18_reset_ir_gpio(void *data)
> -{
> -	struct cx18 *cx = to_cx18(data);
> -
> -	if (cx->card->gpio_i2c_slave_reset.ir_reset_mask == 0)
> -		return;
> -
> -	CX18_DEBUG_INFO("Resetting IR microcontroller\n");
> -
> -	v4l2_subdev_call(&cx->sd_resetctrl,
> -			 core, reset, CX18_GPIO_RESET_Z8F0811);
> -}
> -EXPORT_SYMBOL(cx18_reset_ir_gpio);
> -/* This symbol is exported for use by lirc_pvr150 for the IR-blaster */
> -
>  /* Xceive tuner reset function */
>  int cx18_reset_tuner_gpio(void *dev, int component, int cmd, int value)
>  {
> diff --git a/drivers/media/pci/cx18/cx18-gpio.h b/drivers/media/pci/cx18/cx18-gpio.h
> index 0fa4c7ad2286..8d5797dea7f5 100644
> --- a/drivers/media/pci/cx18/cx18-gpio.h
> +++ b/drivers/media/pci/cx18/cx18-gpio.h
> @@ -17,5 +17,4 @@ enum cx18_gpio_reset_type {
>  	CX18_GPIO_RESET_XC2028  = 2,
>  };
>  
> -void cx18_reset_ir_gpio(void *data);
>  int cx18_reset_tuner_gpio(void *dev, int component, int cmd, int value);
> -- 
> 2.47.0
>