Re: [PATCH v2 11/19] fbcon: move more common code into fb_open()

From: Thomas Zimmermann
Date: Thu Feb 10 2022 - 09:16:55 EST




Am 08.02.22 um 22:08 schrieb Daniel Vetter:
No idea why con2fb_acquire_newinfo() initializes much less than
fbcon_startup(), but so be it. From a quick look most of the
un-initialized stuff should be fairly harmless, but who knows.

Note that the error handling for the con2fb_acquire_newinfo() failure
case was very strange: Callers updated con2fb_map to the new value
before calling this function, but upon error con2fb_acquire_newinfo
reset it to the old value. Since I removed the call to fbcon_release
anyway that strange error path was sticking out like a sore thumb,
hence I removed it. Which also allows us to remove the oldidx
parameter from that function.

v2: Explain what's going on with oldidx and error paths (Sam)

v3: Drop unused variable (0day)

Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> (v2)
Cc: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: Claudio Suarez <cssk@xxxxxxxx>
Cc: Du Cheng <ducheng2@xxxxxxxxx>

Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

That's the init function I was looking for, I guess.

---
drivers/video/fbdev/core/fbcon.c | 75 +++++++++++++-------------------
1 file changed, 30 insertions(+), 45 deletions(-)

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index a60891005d44..f0213a0e3870 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -682,8 +682,18 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)
#endif /* CONFIG_MISC_TILEBLITTING */
+static void fbcon_release(struct fb_info *info)
+{
+ if (info->fbops->fb_release)
+ info->fbops->fb_release(info, 0);
+
+ module_put(info->fbops->owner);
+}
+
static int fbcon_open(struct fb_info *info)
{
+ struct fbcon_ops *ops;
+
if (!try_module_get(info->fbops->owner))
return -ENODEV;
@@ -693,48 +703,31 @@ static int fbcon_open(struct fb_info *info)
return -ENODEV;
}
- return 0;
-}
+ ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
+ if (!ops) {
+ fbcon_release(info);
+ return -ENOMEM;
+ }
-static void fbcon_release(struct fb_info *info)
-{
- if (info->fbops->fb_release)
- info->fbops->fb_release(info, 0);
+ INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);
+ ops->info = info;
+ info->fbcon_par = ops;
+ ops->cur_blink_jiffies = HZ / 5;
- module_put(info->fbops->owner);
+ return 0;
}
static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,
- int unit, int oldidx)
+ int unit)
{
- struct fbcon_ops *ops = NULL;
int err;
err = fbcon_open(info);
if (err)
return err;
- if (!err) {
- ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
- if (!ops)
- err = -ENOMEM;
-
- INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);
- }
-
- if (!err) {
- ops->cur_blink_jiffies = HZ / 5;
- ops->info = info;
- info->fbcon_par = ops;
-
- if (vc)
- set_blitting_type(vc, info);
- }
-
- if (err) {
- con2fb_map[unit] = oldidx;
- fbcon_release(info);
- }
+ if (vc)
+ set_blitting_type(vc, info);
return err;
}
@@ -842,9 +835,11 @@ static int set_con2fb_map(int unit, int newidx, int user)
found = search_fb_in_map(newidx);
- con2fb_map[unit] = newidx;
- if (!err && !found)
- err = con2fb_acquire_newinfo(vc, info, unit, oldidx);
+ if (!err && !found) {
+ err = con2fb_acquire_newinfo(vc, info, unit);
+ if (!err)
+ con2fb_map[unit] = newidx;
+ }
/*
* If old fb is not mapped to any of the consoles,
@@ -941,20 +936,10 @@ static const char *fbcon_startup(void)
if (fbcon_open(info))
return NULL;
- ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
- if (!ops) {
- fbcon_release(info);
- return NULL;
- }
-
- INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);
-
+ ops = info->fbcon_par;
ops->currcon = -1;
ops->graphics = 1;
ops->cur_rotate = -1;
- ops->cur_blink_jiffies = HZ / 5;
- ops->info = info;
- info->fbcon_par = ops;
p->con_rotate = initial_rotation;
if (p->con_rotate == -1)
@@ -1024,7 +1009,7 @@ static void fbcon_init(struct vc_data *vc, int init)
return;
if (!info->fbcon_par)
- con2fb_acquire_newinfo(vc, info, vc->vc_num, -1);
+ con2fb_acquire_newinfo(vc, info, vc->vc_num);
/* If we are not the first console on this
fb, copy the font from that console */

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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