From: Daniel Vetter <daniel@ffwll.ch>
To: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
LKML <linux-kernel@vger.kernel.org>,
Prarit Bhargava <prarit@redhat.com>,
Kees Cook <keescook@chromium.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
DRI Development <dri-devel@lists.freedesktop.org>,
Yisheng Xie <ysxie@foxmail.com>,
Hans de Goede <hdegoede@redhat.com>,
Daniel Vetter <daniel.vetter@intel.com>,
Konstantin Khorenko <khorenko@virtuozzo.com>
Subject: Re: [PATCH 09/33] fbcon: Remove fbcon_has_exited
Date: Mon, 27 May 2019 08:10:42 +0200 [thread overview]
Message-ID: <20190527061042.GF21222@phenom.ffwll.local> (raw)
In-Reply-To: <20190525153826.GA8661@ravnborg.org>
On Sat, May 25, 2019 at 05:38:26PM +0200, Sam Ravnborg wrote:
> Hi Daniel.
>
> One detail I noticed while brosing the changes.
>
> >
> > @@ -1064,9 +1062,13 @@ static void fbcon_init(struct vc_data *vc, int init)
> > int logo = 1, new_rows, new_cols, rows, cols, charcnt = 256;
> > int cap, ret;
> >
> > - if (info_idx == -1 || info == NULL)
> > + if (WARN_ON(info_idx == -1))
> > return;
> >
> > + if (con2fb_map[vc->vc_num] == -1)
> > + con2fb_map[vc->vc_num] = info_idx;
> > +
> > + info = registered_fb[con2fb_map[vc->vc_num]];
> > cap = info->flags;
>
> When info is defined it is also assigned:
> struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
>
> As the test for info is gone this assignment is no longer
> requrired and can be deleted.
We use it later on, so we definitely still need info. But I indeed forgot
to delete the initial assignment of info at the function start. Is that
what you mean here?
>
> The code now assumes that there is always an fb_info if con2fb_map[]
> is not set to -1. I could not determine if this is OK, but this
> likely boils down to your locking concern of registered_fb.
Yup, see how fb_registered/unregistered manage this. I think that part
actually all works out correctly (as long as everyone is holding
console_lock). But it's a bit unpretty that fbcon digs around in the raw
registered_fb array instead of going through the refcounted helpers, and
having a full refcounted pointer. Much easier to convince yourself of that
than chasing indices assigments all over imo.
-Daniel
>
> Sam
>
> >
> > if (logo_shown < 0 && console_loglevel <= CONSOLE_LOGLEVEL_QUIET)
> > @@ -3336,14 +3338,6 @@ static int fbcon_event_notify(struct notifier_block *self,
> > struct fb_blit_caps *caps;
> > int idx, ret = 0;
> >
> > - /*
> > - * ignore all events except driver registration and deregistration
> > - * if fbcon is not active
> > - */
> > - if (fbcon_has_exited && !(action == FB_EVENT_FB_REGISTERED ||
> > - action == FB_EVENT_FB_UNREGISTERED))
> > - goto done;
> > -
> > switch(action) {
> > case FB_EVENT_SUSPEND:
> > fbcon_suspended(info);
> > @@ -3396,7 +3390,6 @@ static int fbcon_event_notify(struct notifier_block *self,
> > fbcon_remap_all(idx);
> > break;
> > }
> > -done:
> > return ret;
> > }
> >
> > @@ -3443,9 +3436,6 @@ static ssize_t store_rotate(struct device *device,
> > int rotate, idx;
> > char **last = NULL;
> >
> > - if (fbcon_has_exited)
> > - return count;
> > -
> > console_lock();
> > idx = con2fb_map[fg_console];
> >
> > @@ -3468,9 +3458,6 @@ static ssize_t store_rotate_all(struct device *device,
> > int rotate, idx;
> > char **last = NULL;
> >
> > - if (fbcon_has_exited)
> > - return count;
> > -
> > console_lock();
> > idx = con2fb_map[fg_console];
> >
> > @@ -3491,9 +3478,6 @@ static ssize_t show_rotate(struct device *device,
> > struct fb_info *info;
> > int rotate = 0, idx;
> >
> > - if (fbcon_has_exited)
> > - return 0;
> > -
> > console_lock();
> > idx = con2fb_map[fg_console];
> >
> > @@ -3514,9 +3498,6 @@ static ssize_t show_cursor_blink(struct device *device,
> > struct fbcon_ops *ops;
> > int idx, blink = -1;
> >
> > - if (fbcon_has_exited)
> > - return 0;
> > -
> > console_lock();
> > idx = con2fb_map[fg_console];
> >
> > @@ -3543,9 +3524,6 @@ static ssize_t store_cursor_blink(struct device *device,
> > int blink, idx;
> > char **last = NULL;
> >
> > - if (fbcon_has_exited)
> > - return count;
> > -
> > console_lock();
> > idx = con2fb_map[fg_console];
> >
> > @@ -3668,9 +3646,6 @@ static void fbcon_exit(void)
> > struct fb_info *info;
> > int i, j, mapped;
> >
> > - if (fbcon_has_exited)
> > - return;
> > -
> > #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
> > if (deferred_takeover) {
> > dummycon_unregister_output_notifier(&fbcon_output_nb);
> > @@ -3695,7 +3670,7 @@ static void fbcon_exit(void)
> > for (j = first_fb_vc; j <= last_fb_vc; j++) {
> > if (con2fb_map[j] == i) {
> > mapped = 1;
> > - break;
> > + con2fb_map[j] = -1;
> > }
> > }
> >
> > @@ -3718,8 +3693,6 @@ static void fbcon_exit(void)
> > info->queue.func = NULL;
> > }
> > }
> > -
> > - fbcon_has_exited = 1;
> > }
> >
> > void __init fb_console_init(void)
> > --
> > 2.20.1
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2019-05-27 6:10 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-24 8:53 [PATCH 00/33] fbcon notifier begone! Daniel Vetter
2019-05-24 8:53 ` [PATCH 01/33] dummycon: Sprinkle locking checks Daniel Vetter
2019-05-24 8:53 ` [PATCH 02/33] fbdev: locking check for fb_set_suspend Daniel Vetter
2019-05-24 8:53 ` [PATCH 03/33] vt: might_sleep() annotation for do_blank_screen Daniel Vetter
2019-05-24 8:53 ` [PATCH 04/33] vt: More locking checks Daniel Vetter
2019-05-27 7:08 ` Daniel Vetter
2019-05-27 7:22 ` Greg Kroah-Hartman
2019-05-24 8:53 ` [PATCH 05/33] fbdev/sa1100fb: Remove dead code Daniel Vetter
2019-05-24 8:53 ` [PATCH 06/33] fbdev/cyber2000: Remove struct display Daniel Vetter
2019-05-24 8:53 ` [PATCH 07/33] fbdev/aty128fb: Remove dead code Daniel Vetter
2019-05-24 8:53 ` [PATCH 08/33] fbcon: s/struct display/struct fbcon_display/ Daniel Vetter
2019-05-24 8:53 ` [PATCH 09/33] fbcon: Remove fbcon_has_exited Daniel Vetter
2019-05-25 15:38 ` Sam Ravnborg
2019-05-27 6:10 ` Daniel Vetter [this message]
2019-05-27 6:51 ` Sam Ravnborg
2019-05-24 8:53 ` [PATCH 10/33] fbcon: call fbcon_fb_(un)registered directly Daniel Vetter
2019-05-24 8:53 ` [PATCH 11/33] fbdev/sh_mobile: remove sh_mobile_lcdc_display_notify Daniel Vetter
2019-05-25 15:01 ` Sam Ravnborg
2019-05-27 6:13 ` Daniel Vetter
2019-05-27 6:52 ` Sam Ravnborg
2019-05-24 8:53 ` [PATCH 12/33] fbdev/omap: sysfs files can't disappear before the device is gone Daniel Vetter
2019-05-24 8:53 ` [PATCH 13/33] fbdev: " Daniel Vetter
2019-05-24 8:53 ` [PATCH 14/33] staging/olpc: lock_fb_info can't fail Daniel Vetter
2019-05-27 7:10 ` Daniel Vetter
2019-05-27 7:22 ` Greg KH
2019-05-24 8:53 ` [PATCH 15/33] fbdev/atyfb: " Daniel Vetter
2019-05-24 8:53 ` [PATCH 16/33] fbdev: lock_fb_info cannot fail Daniel Vetter
2019-05-24 8:53 ` [PATCH 17/33] fbcon: call fbcon_fb_bind directly Daniel Vetter
2019-05-24 8:53 ` [PATCH 18/33] fbdev: make unregister/unlink functions not fail Daniel Vetter
2019-05-24 8:53 ` [PATCH 19/33] fbdev: unify unlink_framebuffer paths Daniel Vetter
2019-05-24 8:53 ` [PATCH 20/33] fbdev/sh_mob: Remove fb notifier callback Daniel Vetter
2019-05-24 8:53 ` [PATCH 21/33] fbdev: directly call fbcon_suspended/resumed Daniel Vetter
2019-05-24 8:53 ` [PATCH 22/33] fbcon: Call fbcon_mode_deleted/new_modelist directly Daniel Vetter
2019-05-24 8:53 ` [PATCH 23/33] fbdev: Call fbcon_get_requirement directly Daniel Vetter
2019-05-24 8:53 ` [PATCH 24/33] Revert "backlight/fbcon: Add FB_EVENT_CONBLANK" Daniel Vetter
2019-05-24 13:14 ` Daniel Thompson
2019-05-24 15:28 ` Daniel Vetter
2019-05-27 10:59 ` Bartlomiej Zolnierkiewicz
2019-05-24 8:53 ` [PATCH 25/33] fbmem: pull fbcon_fb_blanked out of fb_blank Daniel Vetter
2019-05-25 17:00 ` Sam Ravnborg
2019-05-24 8:53 ` [PATCH 26/33] fbdev: remove FBINFO_MISC_USEREVENT around fb_blank Daniel Vetter
2019-05-24 8:53 ` [PATCH 27/33] fb: Flatten control flow in fb_set_var Daniel Vetter
2019-05-24 8:53 ` [PATCH 28/33] fbcon: replace FB_EVENT_MODE_CHANGE/_ALL with direct calls Daniel Vetter
2019-05-24 8:53 ` [PATCH 29/33] vgaswitcheroo: call fbcon_remap_all directly Daniel Vetter
2019-05-24 8:53 ` [PATCH 30/33] fbcon: Call con2fb_map functions directly Daniel Vetter
2019-05-24 8:53 ` [PATCH 31/33] fbcon: Document what I learned about fbcon locking Daniel Vetter
2019-05-24 8:53 ` [PATCH 32/33] staging/olpc_dcon: Add drm conversion to TODO Daniel Vetter
2019-05-27 7:11 ` Daniel Vetter
2019-05-27 7:22 ` Greg KH
2019-05-24 8:53 ` [PATCH 33/33] backlight: simplify lcd notifier Daniel Vetter
2019-05-25 17:19 ` [PATCH 00/33] fbcon notifier begone! Sam Ravnborg
2019-05-27 7:17 ` Daniel Vetter
2019-05-27 11:56 ` Daniel Vetter
-- strict thread matches above, loose matches on Subject: below --
2019-05-28 9:02 [PATCH 00/33] fbcon notifier begone v3! Daniel Vetter
2019-05-28 9:02 ` [PATCH 09/33] fbcon: Remove fbcon_has_exited Daniel Vetter
2019-05-20 8:21 [PATCH 00/33] fbcon notifier begone! Daniel Vetter
2019-05-20 8:21 ` [PATCH 09/33] fbcon: Remove fbcon_has_exited Daniel Vetter
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