Re: [PATCH v2] console: Replace #if 1 with a bool to ignore
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2018-07-12 13:30:55
Also in:
dri-devel, lkml
On Thu, 12 Jul 2018 09:29:38 -0400 Steven Rostedt [off-list ref] wrote:
From: Steven Rostedt (VMware) <rostedt@goodmis.org> There's been discussion on the fb list about the addition of WARN_CONSOLE_UNLOCKED() inside the fb code. The complaint is that when the fb module is loaded with lockless_register_fb the console lock is not taken for debugging reasons. With the addition of WARN_CONSOLE_UNLOCK() within the fb code, this causes the console to fill up with warnings when trying to debug the fb driver. There's also a #if 1 that enables the warning which was added before git history, and we look down on constant #if's in the kernel nowadays anyway. Remove the #if 1 and add a ignore_console_lock_warning boolean that can be set by drivers to ignore the warning in order to do debugging. Link: http://lkml.kernel.org/r/717e6337-e7a6-7a92-1c1b-8929a25696b5@suse.de Reviewed-by: Hans de Goede <redacted> Acked-by: Sergey Senozhatsky <redacted> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Petr, If you want this to go by way of fbdev tree, then can you Ack it? -- Steve
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--- Changes since V1: - Added comment to describe ignore_console_unlock_waring variable - Abide by 80 character limit Index: linux-trace.git/include/linux/console.h =================================> --- linux-trace.git.orig/include/linux/console.h+++ linux-trace.git/include/linux/console.h@@ -200,11 +200,14 @@ void vcs_make_sysfs(int index); void vcs_remove_sysfs(int index); /* Some debug stub to catch some of the obvious races in the VT code */ -#if 1 -#define WARN_CONSOLE_UNLOCKED() WARN_ON(!is_console_locked() && !oops_in_progress) -#else -#define WARN_CONSOLE_UNLOCKED() -#endif +#define WARN_CONSOLE_UNLOCKED() \ + WARN_ON(!ignore_console_lock_warning && \ + !is_console_locked() && !oops_in_progress) +/* + * Set ignore_console_lock_warning to true if you need to quiet + * WARN_CONSOLE_UNLOCKED() for debugging purposes. + */ +extern bool ignore_console_lock_warning; /* VESA Blanking Levels */ #define VESA_NO_BLANKING 0Index: linux-trace.git/kernel/printk/printk.c =================================> --- linux-trace.git.orig/kernel/printk/printk.c+++ linux-trace.git/kernel/printk/printk.c@@ -66,6 +66,9 @@ int console_printk[4] = { CONSOLE_LOGLEVEL_DEFAULT, /* default_console_loglevel */ }; +bool ignore_console_lock_warning __read_mostly; +EXPORT_SYMBOL(ignore_console_lock_warning); + /* * Low level drivers may need that to know if they can schedule in * their unblank() callback or not. So let's export it.