2022-02-09 07:50:51

by Daniel Vetter

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

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 <[email protected]> (v2)
Cc: kernel test robot <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Claudio Suarez <[email protected]>
Cc: Du Cheng <[email protected]>
---
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 */
--
2.34.1



2022-02-11 01:31:05

by Thomas Zimmermann

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



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 <[email protected]> (v2)
> Cc: kernel test robot <[email protected]>
> Signed-off-by: Daniel Vetter <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: Tetsuo Handa <[email protected]>
> Cc: Thomas Zimmermann <[email protected]>
> Cc: Claudio Suarez <[email protected]>
> Cc: Du Cheng <[email protected]>

Acked-by: Thomas Zimmermann <[email protected]>

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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