Re: [PATCH v5 2/3] fbcon: Call WARN_CONSOLE_UNLOCKED() where applicable

[Thomas Zimmermann]

Hi

Am 11.07.2018 um 16:52 schrieb Steven Rostedt:
> 
> What if you make lockless_register_fb visible to fbcon, and then we can
> have a macro:

There are more of these macro invocations under drivers/tty/vt, which
also mess up the log during debugging.

WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else
...' construct [1]. I thought about turning this into a config option.

Best regards
Thomas

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/console.h#n203

> 
> #define WARN_FB_CONSOLE_UNLOCKED() 			\
> 	do {						\
> 		if (unlikely(!lockless_register_fb))	\
> 			WARN_CONSOLE_UNLOCKED();	\
> 	} while (0)
> 
> And use that instead?
> 
> -- Steve
> 
> 
>> Best regards
>> Thomas
>>
>>> Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
>>> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
>>> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
>>> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>>> ---
>>> Changes in v3:
>>> -New patch in v3 of this patchset
>>>
>>> Changes in v4:
>>> -Keep the comments about which fbcon functions need locks in place
>>> ---
>>>  drivers/video/fbdev/core/fbcon.c | 11 +++++++++++
>>>  1 file changed, 11 insertions(+)
>>>
>>> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
>>> index c910e74d46ff..cd8d52a967aa 100644
>>> --- a/drivers/video/fbdev/core/fbcon.c
>>> +++ b/drivers/video/fbdev/core/fbcon.c
>>> @@ -828,6 +828,8 @@ static int set_con2fb_map(int unit, int newidx, int user)
>>>  	struct fb_info *oldinfo = NULL;
>>>   	int found, err = 0;
>>>  
>>> +	WARN_CONSOLE_UNLOCKED();
>>> +
>>>  	if (oldidx == newidx)
>>>  		return 0;
>>>  
>>> @@ -3044,6 +3046,8 @@ static int fbcon_fb_unbind(int idx)
>>>  {
>>>  	int i, new_idx = -1, ret = 0;
>>>  
>>> +	WARN_CONSOLE_UNLOCKED();
>>> +
>>>  	if (!fbcon_has_console_bind)
>>>  		return 0;
>>>  
>>> @@ -3094,6 +3098,8 @@ static int fbcon_fb_unregistered(struct fb_info *info)
>>>  {
>>>  	int i, idx;
>>>  
>>> +	WARN_CONSOLE_UNLOCKED();
>>> +
>>>  	idx = info->node;
>>>  	for (i = first_fb_vc; i <= last_fb_vc; i++) {
>>>  		if (con2fb_map[i] == idx)
>>> @@ -3131,6 +3137,9 @@ static int fbcon_fb_unregistered(struct fb_info *info)
>>>  static void fbcon_remap_all(int idx)
>>>  {
>>>  	int i;
>>> +
>>> +	WARN_CONSOLE_UNLOCKED();
>>> +
>>>  	for (i = first_fb_vc; i <= last_fb_vc; i++)
>>>  		set_con2fb_map(i, idx, 0);
>>>  
>>> @@ -3177,6 +3186,8 @@ static int fbcon_fb_registered(struct fb_info *info)
>>>  {
>>>  	int ret = 0, i, idx;
>>>  
>>> +	WARN_CONSOLE_UNLOCKED();
>>> +
>>>  	idx = info->node;
>>>  	fbcon_select_primary(info);
>>>    
>>
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstr. 5, D-90409 NÃrnberg
Tel: +49-911-74053-0; Fax: +49-911-7417755;  https://www.suse.com/
SUSE Linux GmbH, GF: Felix ImendÃrffer, Jane Smithard,
Graham Norton, HRB 21284 (AG NÃrnberg)

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