[PATCH] tty/vt: Remove printable variable

[PATCH] tty/vt: Remove printable variable

[Daniel Vetter]

Every since the 0.99.7A release when console_register() was introduced
it's become impossible to call vt_console_print (called
console_print() back then still) directly. Which means the
initialization issue this variable protected against is no more.

Give it a send off with style and let it rest in peace.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: nick black <dankamongmen@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Yangxi Xiang <xyangxi5@gmail.com>
Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
---
 drivers/tty/vt/vt.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index ae9c926acd6f..4d29e4a17db7 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -157,7 +157,6 @@ static void set_palette(struct vc_data *vc);
 
 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 
-static int printable;		/* Is console ready for printing? */
 int default_utf8 = true;
 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 int global_cursor_default = -1;
@@ -3085,8 +3084,6 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
 	int kmsg_console;
 
 	/* console busy or not yet initialized */
-	if (!printable)
-		return;
 	if (!spin_trylock(&printing_lock))
 		return;
 
@@ -3537,7 +3534,6 @@ static int __init con_init(void)
 	pr_info("Console: %s %s %dx%d\n",
 		vc->vc_can_do_color ? "colour" : "mono",
 		display_desc, vc->vc_cols, vc->vc_rows);
-	printable = 1;
 
 	console_unlock();
 
-- 
2.37.2

Re: [PATCH] tty/vt: Remove printable variable

[Sam Ravnborg]

Hi Daniel,

On Fri, Aug 26, 2022 at 10:24:19PM +0200, Daniel Vetter wrote:
> Every since the 0.99.7A release when console_register() was introduced
> it's become impossible to call vt_console_print (called
> console_print() back then still) directly. Which means the
> initialization issue this variable protected against is no more.
> 
> Give it a send off with style and let it rest in peace.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
> Cc: nick black <dankamongmen@gmail.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: Yangxi Xiang <xyangxi5@gmail.com>
> Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
> ---
>  drivers/tty/vt/vt.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index ae9c926acd6f..4d29e4a17db7 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -157,7 +157,6 @@ static void set_palette(struct vc_data *vc);
>  
>  #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
>  
> -static int printable;		/* Is console ready for printing? */
>  int default_utf8 = true;
>  module_param(default_utf8, int, S_IRUGO | S_IWUSR);
>  int global_cursor_default = -1;
> @@ -3085,8 +3084,6 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
>  	int kmsg_console;
>  
>  	/* console busy or not yet initialized */
> -	if (!printable)
> -		return;
>  	if (!spin_trylock(&printing_lock))
>  		return;

Speaking on locks - it the printing_lock necessary. Or will the caller
serialize the calls to write()?

	Sam

>  
> @@ -3537,7 +3534,6 @@ static int __init con_init(void)
>  	pr_info("Console: %s %s %dx%d\n",
>  		vc->vc_can_do_color ? "colour" : "mono",
>  		display_desc, vc->vc_cols, vc->vc_rows);
> -	printable = 1;
>  
>  	console_unlock();
>  
> -- 
> 2.37.2

Re: [PATCH] tty/vt: Remove printable variable

[Jiri Slaby]

On 26. 08. 22, 22:24, Daniel Vetter wrote:
> Every since the 0.99.7A release when console_register() was introduced
> it's become impossible to call vt_console_print (called
> console_print() back then still) directly. Which means the
> initialization issue this variable protected against is no more.
> 
> Give it a send off with style and let it rest in peace.

FWIW:
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

In hopes, nothing breaks.

> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
> Cc: nick black <dankamongmen@gmail.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: Yangxi Xiang <xyangxi5@gmail.com>
> Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
> ---
>   drivers/tty/vt/vt.c | 4 ----
>   1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index ae9c926acd6f..4d29e4a17db7 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -157,7 +157,6 @@ static void set_palette(struct vc_data *vc);
>   
>   #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
>   
> -static int printable;		/* Is console ready for printing? */
>   int default_utf8 = true;
>   module_param(default_utf8, int, S_IRUGO | S_IWUSR);
>   int global_cursor_default = -1;
> @@ -3085,8 +3084,6 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
>   	int kmsg_console;
>   
>   	/* console busy or not yet initialized */
> -	if (!printable)
> -		return;
>   	if (!spin_trylock(&printing_lock))
>   		return;
>   
> @@ -3537,7 +3534,6 @@ static int __init con_init(void)
>   	pr_info("Console: %s %s %dx%d\n",
>   		vc->vc_can_do_color ? "colour" : "mono",
>   		display_desc, vc->vc_cols, vc->vc_rows);
> -	printable = 1;
>   
>   	console_unlock();
>   

thanks,
-- 
js
suse labs

Re: [PATCH] tty/vt: Remove printable variable

[Sam Ravnborg]

Hi Daniel,

On Tue, Aug 30, 2022 at 03:41:17PM +0200, Daniel Vetter wrote:
> Every since the 0.99.7A release when console_register() was introduced
> it's become impossible to call vt_console_print (called
> console_print() back then still) directly. Which means the
> initialization issue this variable protected against is no more.
> 
> Give it a send off with style and let it rest in peace.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
> Cc: nick black <dankamongmen@gmail.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: Yangxi Xiang <xyangxi5@gmail.com>
> Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>

I saw this was sent again on accident, but that sdoes not prevent me
from adding a:
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

I was a bit reluctant to r-b it, but well this looks obviously correct,
so ...

	Sam

Re: [PATCH] tty/vt: Remove printable variable

[Daniel Vetter]

On Tue, Aug 30, 2022 at 03:41:17PM +0200, Daniel Vetter wrote:
> Every since the 0.99.7A release when console_register() was introduced
> it's become impossible to call vt_console_print (called
> console_print() back then still) directly. Which means the
> initialization issue this variable protected against is no more.
> 
> Give it a send off with style and let it rest in peace.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
> Cc: nick black <dankamongmen@gmail.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: Yangxi Xiang <xyangxi5@gmail.com>
> Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>

Please disregard this, sent it accidentally instead of v2 of "tty/vt: Add
console_lock check to vt_console_print()".
-Daniel

> ---
>  drivers/tty/vt/vt.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index ae9c926acd6f..4d29e4a17db7 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -157,7 +157,6 @@ static void set_palette(struct vc_data *vc);
>  
>  #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
>  
> -static int printable;		/* Is console ready for printing? */
>  int default_utf8 = true;
>  module_param(default_utf8, int, S_IRUGO | S_IWUSR);
>  int global_cursor_default = -1;
> @@ -3085,8 +3084,6 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
>  	int kmsg_console;
>  
>  	/* console busy or not yet initialized */
> -	if (!printable)
> -		return;
>  	if (!spin_trylock(&printing_lock))
>  		return;
>  
> @@ -3537,7 +3534,6 @@ static int __init con_init(void)
>  	pr_info("Console: %s %s %dx%d\n",
>  		vc->vc_can_do_color ? "colour" : "mono",
>  		display_desc, vc->vc_cols, vc->vc_rows);
> -	printable = 1;
>  
>  	console_unlock();
>  
> -- 
> 2.37.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

[PATCH] tty/vt: Remove printable variable

[Daniel Vetter]

Every since the 0.99.7A release when console_register() was introduced
it's become impossible to call vt_console_print (called
console_print() back then still) directly. Which means the
initialization issue this variable protected against is no more.

Give it a send off with style and let it rest in peace.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: nick black <dankamongmen@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Yangxi Xiang <xyangxi5@gmail.com>
Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
---
 drivers/tty/vt/vt.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index ae9c926acd6f..4d29e4a17db7 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -157,7 +157,6 @@ static void set_palette(struct vc_data *vc);
 
 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 
-static int printable;		/* Is console ready for printing? */
 int default_utf8 = true;
 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 int global_cursor_default = -1;
@@ -3085,8 +3084,6 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
 	int kmsg_console;
 
 	/* console busy or not yet initialized */
-	if (!printable)
-		return;
 	if (!spin_trylock(&printing_lock))
 		return;
 
@@ -3537,7 +3534,6 @@ static int __init con_init(void)
 	pr_info("Console: %s %s %dx%d\n",
 		vc->vc_can_do_color ? "colour" : "mono",
 		display_desc, vc->vc_cols, vc->vc_rows);
-	printable = 1;
 
 	console_unlock();
 
-- 
2.37.2