On Wed, Jul 11, 2018 at 5:14 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > Hi, > > On 11-07-18 17:07, Thomas Zimmermann wrote: >> >> 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. > > > Hmm, so this option is already broken (in a way) then, my first reaction > to your mail was that we should just remove that option. But that seemed > a bit harsh to me so I've been working on a fix for the last 10 minutes > or so. > > But if it is already broken I'm tempted to just remove the option and > be done with it. We really need less cruft in the fbdev/fbcon code not > more. Please don't remove it, it makes debugging kms driver issues on initial modeset (which is usually run from framebuffer_register, while hodling the console_lock) impossible. -Daniel >> WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else >> ...' construct [1]. I thought about turning this into a config option. > > > Ah I noticed the #if but I did not notice that it was a "#if 1". > > If you want to fix lockless_register_fb it really should be replaced > with a runtime check, not a Kconfig option. This would require having > some lockless variable in the console code itself, which then gets > set by the fbdev code during init based on its lockless_register_fb > setting. > > But as said I think we should seriously consider just removing > lockless_register_fb. > > Regards, > > Hans > > > > > > > >> >> 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); >>>>> >>>> >>>> >>> >> > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
