diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2019-05-28 11:02:56 +0200 |
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committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2019-06-12 20:30:00 +0200 |
commit | de29ae5c092bd9a5360cfabf174b0f783248d278 (patch) | |
tree | caebbd07fb21b024914cefb2aaea588c52e3a28e /drivers/video/fbdev | |
parent | 7a625549ea8c14be70bc7cfaf30215401bba6da0 (diff) | |
download | linux-stable-de29ae5c092bd9a5360cfabf174b0f783248d278.tar.gz linux-stable-de29ae5c092bd9a5360cfabf174b0f783248d278.tar.bz2 linux-stable-de29ae5c092bd9a5360cfabf174b0f783248d278.zip |
fbmem: pull fbcon_fb_blanked out of fb_blank
There's a callchain of:
fbcon_fb_blanked -> do_(un)blank_screen -> consw->con_blank
-> fbcon_blank -> fb_blank
Things don't go horribly wrong because the BKL console_lock safes the
day, but that's about it. And the seeming recursion is broken in 2
ways:
- Starting from the fbdev ioctl we set FBINFO_MISC_USEREVENT, which
tells the fbcon_blank code to not call fb_blank. This was required
to not deadlock when recursing on the fb_notifier_chain mutex.
- Starting from the con_blank hook we're getting saved by the
console_blanked checks in do_blank/unblank_screen. Or at least
that's my theory.
Anyway, recursion isn't awesome, so let's stop it. Breaking the
recursion avoids the need to be in the FBINFO_MISC_USEREVENT critical
section, so lets move it out of that too.
The astute reader will notice that fb_blank seems to require
lock_fb_info(), which the fbcon code seems to ignore. I have no idea
how to fix that problem, so let's keep ignoring it.
v2: I forgot the sysfs blanking code.
v3: Fix typo in callchain in the commmit message (Sam).
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-26-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/video/fbdev')
-rw-r--r-- | drivers/video/fbdev/core/fbmem.c | 4 | ||||
-rw-r--r-- | drivers/video/fbdev/core/fbsysfs.c | 8 |
2 files changed, 9 insertions, 3 deletions
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 9366fbe99a58..d6713dce9e31 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1068,7 +1068,6 @@ fb_blank(struct fb_info *info, int blank) event.data = ␣ early_ret = fb_notifier_call_chain(FB_EARLY_EVENT_BLANK, &event); - fbcon_fb_blanked(info, blank); if (info->fbops->fb_blank) ret = info->fbops->fb_blank(blank, info); @@ -1198,6 +1197,9 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, info->flags |= FBINFO_MISC_USEREVENT; ret = fb_blank(info, arg); info->flags &= ~FBINFO_MISC_USEREVENT; + + /* might again call into fb_blank */ + fbcon_fb_blanked(info, arg); unlock_fb_info(info); console_unlock(); break; diff --git a/drivers/video/fbdev/core/fbsysfs.c b/drivers/video/fbdev/core/fbsysfs.c index f80d5b3a7797..6e39066774a6 100644 --- a/drivers/video/fbdev/core/fbsysfs.c +++ b/drivers/video/fbdev/core/fbsysfs.c @@ -14,6 +14,7 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/fb.h> +#include <linux/fbcon.h> #include <linux/console.h> #include <linux/module.h> @@ -301,12 +302,15 @@ static ssize_t store_blank(struct device *device, { struct fb_info *fb_info = dev_get_drvdata(device); char *last = NULL; - int err; + int err, arg; + arg = simple_strtoul(buf, &last, 0); console_lock(); fb_info->flags |= FBINFO_MISC_USEREVENT; - err = fb_blank(fb_info, simple_strtoul(buf, &last, 0)); + err = fb_blank(fb_info, arg); fb_info->flags &= ~FBINFO_MISC_USEREVENT; + /* might again call into fb_blank */ + fbcon_fb_blanked(fb_info, arg); console_unlock(); if (err < 0) return err; |