Re: [PATCH v2 11/19] fbcon: move more common code into fb_open()

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Am 08.02.22 um 22:08 schrieb Daniel Vetter:
> No idea why con2fb_acquire_newinfo() initializes much less than
> fbcon_startup(), but so be it. From a quick look most of the
> un-initialized stuff should be fairly harmless, but who knows.
>
> Note that the error handling for the con2fb_acquire_newinfo() failure
> case was very strange: Callers updated con2fb_map to the new value
> before calling this function, but upon error con2fb_acquire_newinfo
> reset it to the old value. Since I removed the call to fbcon_release
> anyway that strange error path was sticking out like a sore thumb,
> hence I removed it. Which also allows us to remove the oldidx
> parameter from that function.
>
> v2: Explain what's going on with oldidx and error paths (Sam)
>
> v3: Drop unused variable (0day)
>
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> (v2)
> Cc: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: Claudio Suarez <cssk@xxxxxxxx>
> Cc: Du Cheng <ducheng2@xxxxxxxxx>

Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

That's the init function I was looking for, I guess.

> ---
>   drivers/video/fbdev/core/fbcon.c | 75 +++++++++++++-------------------
>   1 file changed, 30 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> index a60891005d44..f0213a0e3870 100644
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -682,8 +682,18 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)
>   
>   #endif /* CONFIG_MISC_TILEBLITTING */
>   
> +static void fbcon_release(struct fb_info *info)
> +{
> +	if (info->fbops->fb_release)
> +		info->fbops->fb_release(info, 0);
> +
> +	module_put(info->fbops->owner);
> +}
> +
>   static int fbcon_open(struct fb_info *info)
>   {
> +	struct fbcon_ops *ops;
> +
>   	if (!try_module_get(info->fbops->owner))
>   		return -ENODEV;
>   
> @@ -693,48 +703,31 @@ static int fbcon_open(struct fb_info *info)
>   		return -ENODEV;
>   	}
>   
> -	return 0;
> -}
> +	ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
> +	if (!ops) {
> +		fbcon_release(info);
> +		return -ENOMEM;
> +	}
>   
> -static void fbcon_release(struct fb_info *info)
> -{
> -	if (info->fbops->fb_release)
> -		info->fbops->fb_release(info, 0);
> +	INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);
> +	ops->info = info;
> +	info->fbcon_par = ops;
> +	ops->cur_blink_jiffies = HZ / 5;
>   
> -	module_put(info->fbops->owner);
> +	return 0;
>   }
>   
>   static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,
> -				  int unit, int oldidx)
> +				  int unit)
>   {
> -	struct fbcon_ops *ops = NULL;
>   	int err;
>   
>   	err = fbcon_open(info);
>   	if (err)
>   		return err;
>   
> -	if (!err) {
> -		ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
> -		if (!ops)
> -			err = -ENOMEM;
> -
> -		INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);
> -	}
> -
> -	if (!err) {
> -		ops->cur_blink_jiffies = HZ / 5;
> -		ops->info = info;
> -		info->fbcon_par = ops;
> -
> -		if (vc)
> -			set_blitting_type(vc, info);
> -	}
> -
> -	if (err) {
> -		con2fb_map[unit] = oldidx;
> -		fbcon_release(info);
> -	}
> +	if (vc)
> +		set_blitting_type(vc, info);
>   
>   	return err;
>   }
> @@ -842,9 +835,11 @@ static int set_con2fb_map(int unit, int newidx, int user)
>   
>   	found = search_fb_in_map(newidx);
>   
> -	con2fb_map[unit] = newidx;
> -	if (!err && !found)
> -		err = con2fb_acquire_newinfo(vc, info, unit, oldidx);
> +	if (!err && !found) {
> +		err = con2fb_acquire_newinfo(vc, info, unit);
> +		if (!err)
> +			con2fb_map[unit] = newidx;
> +	}
>   
>   	/*
>   	 * If old fb is not mapped to any of the consoles,
> @@ -941,20 +936,10 @@ static const char *fbcon_startup(void)
>   	if (fbcon_open(info))
>   		return NULL;
>   
> -	ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
> -	if (!ops) {
> -		fbcon_release(info);
> -		return NULL;
> -	}
> -
> -	INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);
> -
> +	ops = info->fbcon_par;
>   	ops->currcon = -1;
>   	ops->graphics = 1;
>   	ops->cur_rotate = -1;
> -	ops->cur_blink_jiffies = HZ / 5;
> -	ops->info = info;
> -	info->fbcon_par = ops;
>   
>   	p->con_rotate = initial_rotation;
>   	if (p->con_rotate == -1)
> @@ -1024,7 +1009,7 @@ static void fbcon_init(struct vc_data *vc, int init)
>   		return;
>   
>   	if (!info->fbcon_par)
> -		con2fb_acquire_newinfo(vc, info, vc->vc_num, -1);
> +		con2fb_acquire_newinfo(vc, info, vc->vc_num);
>   
>   	/* If we are not the first console on this
>   	   fb, copy the font from that console */

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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