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From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: "DRI Development" <dri-devel@lists.freedesktop.org>,
	"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"Daniel Vetter" <daniel.vetter@intel.com>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Hans de Goede" <hdegoede@redhat.com>,
	"Noralf Trønnes" <noralf@tronnes.org>,
	"Yisheng Xie" <ysxie@foxmail.com>,
	"Konstantin Khorenko" <khorenko@virtuozzo.com>,
	"Prarit Bhargava" <prarit@redhat.com>,
	"Kees Cook" <keescook@chromium.org>
Subject: Re: [PATCH] fbcon: Remove fbcon_has_exited
Date: Wed, 22 May 2019 12:38:18 +0200	[thread overview]
Message-ID: <CAKMK7uGKxny2cM9wPBvu9jRUKR0KP2OOHa8qAsReNsKWTvscAA@mail.gmail.com> (raw)
In-Reply-To: <6b9747cf-8845-0eb9-878e-f2953665fcec@samsung.com>

On Wed, May 22, 2019 at 12:04 PM Bartlomiej Zolnierkiewicz
<b.zolnierkie@samsung.com> wrote:
>
>
> Hi Daniel,
>
> On 5/21/19 4:23 PM, Daniel Vetter wrote:
> > This is unused code since
> >
> > commit 6104c37094e729f3d4ce65797002112735d49cd1
> > Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Date:   Tue Aug 1 17:32:07 2017 +0200
> >
> >     fbcon: Make fbcon a built-time depency for fbdev
> >
> > when fbcon was made a compile-time static dependency of fbdev. We
> > can't exit fbcon anymore without exiting fbdev first, which only works
> > if all fbdev drivers have unloaded already. Hence this is all dead
> > code.
> >
> > v2: I missed that fbcon_exit is also called from con_deinit stuff, and
> > there fbcon_has_exited prevents double-cleanup. But we can fix that
> > by properly resetting con2fb_map[] to all -1, which is used everywhere
> > else to indicate "no fb_info allocate to this console". With that
> > change the double-cleanup (which resulted in a module refcount underflow,
> > among other things) is prevented.
> >
> > Aside: con2fb_map is a signed char, so don't register more than 128 fb_info
> > or hilarity will ensue.
> >
> > v3: CI showed me that I still didn't fully understand what's going on
> > here. The leaked references in con2fb_map have been used upon
> > rebinding the fb console in fbcon_init. It worked because fbdev
> > unregistering still cleaned out con2fb_map, and reset it to info_idx.
> > If the last fbdev driver unregistered, then it also reset info_idx,
> > and unregistered the fbcon driver.
> >
> > Imo that's all a bit fragile, so let's keep the con2fb_map reset to
> > -1, and in fbcon_init pick info_idx if we're starting fresh. That
> > means unbinding and rebinding will cleanse the mapping, but why are
> > you doing that if you want to retain the mapping, so should be fine.
> >
> > Also, I think info_idx == -1 is impossible in fbcon_init - we
> > unregister the fbcon in that case. So catch&warn about that.
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Cc: Hans de Goede <hdegoede@redhat.com>
> > Cc: "Noralf Trønnes" <noralf@tronnes.org>
> > Cc: Yisheng Xie <ysxie@foxmail.com>
> > Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
> > Cc: Prarit Bhargava <prarit@redhat.com>
> > Cc: Kees Cook <keescook@chromium.org>
> > ---
> >  drivers/video/fbdev/core/fbcon.c | 39 +++++---------------------------
> >  1 file changed, 6 insertions(+), 33 deletions(-)
> This patch was #09/33 in your patch series, now it is independent change.
>
> Do you want me to apply it now or should I wait for the new version of
> the whole series?

It's an in-reply-to replacement for the totally broken one, so that
patchwork picks things up correctly (and therefore our CI). I'm not
sure how far that convention is used beyond dri-devel ...

I did fix up all the issues pointed out thus far, but I haven't fully
appeased our CI just yet. Once that's done I'll resend.

Thanks, Daniel

> [ I looked at all patches in the series and they look fine to me.
>   After outstanding issues are fixed I'll be happy to apply them all
>   to fbdev-for-next (I can create immutable branch if needed). ]
>
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

  reply	other threads:[~2019-05-22 10:38 UTC|newest]

Thread overview: 112+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-20  8:21 [PATCH 00/33] fbcon notifier begone! Daniel Vetter
2019-05-20  8:21 ` [PATCH 01/33] dummycon: Sprinkle locking checks Daniel Vetter
2019-05-20  8:21 ` [PATCH 02/33] fbdev: locking check for fb_set_suspend Daniel Vetter
2019-05-20  8:21 ` [PATCH 03/33] vt: might_sleep() annotation for do_blank_screen Daniel Vetter
2019-05-20  8:21 ` [PATCH 04/33] vt: More locking checks Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 05/33] fbdev/sa1100fb: Remove dead code Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 06/33] fbdev/cyber2000: Remove struct display Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 07/33] fbdev/aty128fb: Remove dead code Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 08/33] fbcon: s/struct display/struct fbcon_display/ Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 09/33] fbcon: Remove fbcon_has_exited Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-21 14:23   ` [PATCH] " Daniel Vetter
2019-05-22 10:04     ` Bartlomiej Zolnierkiewicz
2019-05-22 10:04       ` Bartlomiej Zolnierkiewicz
2019-05-22 10:38       ` Daniel Vetter [this message]
2019-05-20  8:21 ` [PATCH 10/33] fbcon: call fbcon_fb_(un)registered directly Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:33   ` Thomas Zimmermann
2019-05-20  8:33     ` Thomas Zimmermann
2019-05-20  8:37     ` Thomas Zimmermann
2019-05-20  8:37       ` Thomas Zimmermann
2019-05-21 15:09       ` Daniel Vetter
2019-05-21 15:09         ` Daniel Vetter
2019-05-20 17:08   ` Sam Ravnborg
2019-05-20 17:08     ` Sam Ravnborg
2019-05-20 17:08     ` Sam Ravnborg
2019-05-20 17:25     ` Daniel Vetter
2019-05-20 17:25       ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 11/33] fbdev/sh_mobile: remove sh_mobile_lcdc_display_notify Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  9:04   ` Geert Uytterhoeven
2019-05-20  8:21 ` [PATCH 12/33] fbdev/omap: sysfs files can't disappear before the device is gone Daniel Vetter
2019-05-20  8:21 ` [PATCH 13/33] fbdev: " Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 14/33] staging/olpc: lock_fb_info can't fail Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 15/33] fbdev/atyfb: " Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:21 ` [PATCH 16/33] fbdev: lock_fb_info cannot fail Daniel Vetter
2019-05-20  8:21   ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 17/33] fbcon: call fbcon_fb_bind directly Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 18/33] fbdev: make unregister/unlink functions not fail Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20 19:08   ` [Intel-gfx] " kbuild test robot
2019-05-20 19:08     ` kbuild test robot
2019-05-20 19:08     ` kbuild test robot
2019-05-20 19:25   ` kbuild test robot
2019-05-20 19:25     ` kbuild test robot
2019-05-20 19:25     ` [Intel-gfx] " kbuild test robot
2019-05-20 21:45   ` kbuild test robot
2019-05-20 21:45     ` kbuild test robot
2019-05-20 21:45     ` kbuild test robot
2019-05-20  8:22 ` [PATCH 19/33] fbdev: unify unlink_framebufer paths Daniel Vetter
2019-05-21 10:52   ` Maarten Lankhorst
2019-05-20  8:22 ` [PATCH 20/33] fbdev/sh_mob: Remove fb notifier callback Daniel Vetter
2019-05-20  9:05   ` Geert Uytterhoeven
2019-05-20  9:19     ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 21/33] fbdev: directly call fbcon_suspended/resumed Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20 19:24   ` kbuild test robot
2019-05-20 19:24     ` kbuild test robot
2019-05-20 19:24     ` kbuild test robot
2019-05-20  8:22 ` [PATCH 22/33] fbcon: Call fbcon_mode_deleted/new_modelist directly Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 23/33] fbdev: Call fbcon_get_requirement directly Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 24/33] Revert "backlight/fbcon: Add FB_EVENT_CONBLANK" Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 25/33] fbcon: directly call fbcon_fb_blanked Daniel Vetter
2019-05-20  8:22 ` [PATCH 26/33] fbmem: pull fbcon_fb_blanked out of fb_blank Daniel Vetter
2019-05-20  8:22 ` [PATCH 27/33] fbdev: remove FBINFO_MISC_USEREVENT around fb_blank Daniel Vetter
2019-05-20 17:20   ` Sam Ravnborg
2019-05-20 17:20     ` Sam Ravnborg
2019-05-20 17:29     ` Daniel Vetter
2019-05-20 17:29       ` Daniel Vetter
2019-05-20 17:53       ` Sam Ravnborg
2019-05-20  8:22 ` [PATCH 28/33] fb: Flatten control flow in fb_set_var Daniel Vetter
2019-05-20  8:22 ` [PATCH 29/33] fbcon: replace FB_EVENT_MODE_CHANGE/_ALL with direct calls Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-21 10:56   ` Maarten Lankhorst
2019-05-21 10:56     ` Maarten Lankhorst
2019-05-21 12:42     ` Daniel Vetter
2019-05-21 12:42       ` Daniel Vetter
2019-05-21 12:42       ` Daniel Vetter
2019-05-20  8:22 ` [PATCH 30/33] vgaswitcheroo: call fbcon_remap_all directly Daniel Vetter
2019-05-20  8:22   ` Daniel Vetter
2019-05-20  8:37   ` Lukas Wunner
2019-05-20  8:37     ` Lukas Wunner
2019-05-20  8:22 ` [PATCH 31/33] fbcon: Call con2fb_map functions directly Daniel Vetter
2019-05-20 19:28   ` [Intel-gfx] " kbuild test robot
2019-05-20 19:28     ` kbuild test robot
2019-05-20 19:34   ` [Intel-gfx] " kbuild test robot
2019-05-20 19:34     ` kbuild test robot
2019-05-20  8:22 ` [PATCH 32/33] fbcon: Document what I learned about fbcon locking Daniel Vetter
2019-05-21 11:13   ` Maarten Lankhorst
2019-05-20  8:22 ` [PATCH 33/33] staging/olpc_dcon: Add drm conversion to TODO Daniel Vetter
2019-05-20  8:30 ` ✗ Fi.CI.CHECKPATCH: warning for fbcon notifier begone! Patchwork
2019-05-20  8:41 ` ✗ Fi.CI.BAT: failure " Patchwork
2019-05-20  8:44 ` ✗ Fi.CI.SPARSE: warning " Patchwork
2019-05-21 17:08 ` ✗ Fi.CI.CHECKPATCH: warning for fbcon notifier begone! (rev2) Patchwork
2019-05-21 17:22 ` ✗ Fi.CI.SPARSE: " Patchwork
2019-05-21 17:29 ` ✗ Fi.CI.BAT: failure " Patchwork
2019-05-22  8:15 ` ✓ Fi.CI.BAT: success " Patchwork
2019-05-22 18:43 ` ✓ Fi.CI.IGT: " Patchwork

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