Commit bd6026a8 authored by Daniel Vetter's avatar Daniel Vetter

fbcon: Extract fbcon_open/release helpers

There's two minor behaviour changes in here:
- in error paths we now consistently call fb_ops->fb_release
- fb_release really can't fail (fbmem.c ignores it too) and there's no
  reasonable cleanup we can do anyway.

Note that everything in fbcon.c is protected by the big console_lock()
lock (especially all the global variables), so the minor changes in
ordering of setup/cleanup do not matter.

v2: Explain a bit better why this is all correct (Sam)
Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Du Cheng <ducheng2@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-10-daniel.vetter@ffwll.ch
parent 6b2060cf
...@@ -682,19 +682,37 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount) ...@@ -682,19 +682,37 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)
#endif /* CONFIG_MISC_TILEBLITTING */ #endif /* CONFIG_MISC_TILEBLITTING */
static int fbcon_open(struct fb_info *info)
{
if (!try_module_get(info->fbops->owner))
return -ENODEV;
if (info->fbops->fb_open &&
info->fbops->fb_open(info, 0)) {
module_put(info->fbops->owner);
return -ENODEV;
}
return 0;
}
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 con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,
int unit, int oldidx) int unit, int oldidx)
{ {
struct fbcon_ops *ops = NULL; struct fbcon_ops *ops = NULL;
int err = 0; int err;
if (!try_module_get(info->fbops->owner))
err = -ENODEV;
if (!err && info->fbops->fb_open && err = fbcon_open(info);
info->fbops->fb_open(info, 0)) if (err)
err = -ENODEV; return err;
if (!err) { if (!err) {
ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
...@@ -715,7 +733,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, ...@@ -715,7 +733,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,
if (err) { if (err) {
con2fb_map[unit] = oldidx; con2fb_map[unit] = oldidx;
module_put(info->fbops->owner); fbcon_release(info);
} }
return err; return err;
...@@ -726,45 +744,34 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, ...@@ -726,45 +744,34 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo,
int oldidx, int found) int oldidx, int found)
{ {
struct fbcon_ops *ops = oldinfo->fbcon_par; struct fbcon_ops *ops = oldinfo->fbcon_par;
int err = 0, ret; int ret;
if (oldinfo->fbops->fb_release && fbcon_release(oldinfo);
oldinfo->fbops->fb_release(oldinfo, 0)) {
con2fb_map[unit] = oldidx;
if (!found && newinfo->fbops->fb_release)
newinfo->fbops->fb_release(newinfo, 0);
if (!found)
module_put(newinfo->fbops->owner);
err = -ENODEV;
}
if (!err) { fbcon_del_cursor_work(oldinfo);
fbcon_del_cursor_work(oldinfo); kfree(ops->cursor_state.mask);
kfree(ops->cursor_state.mask); kfree(ops->cursor_data);
kfree(ops->cursor_data); kfree(ops->cursor_src);
kfree(ops->cursor_src); kfree(ops->fontbuffer);
kfree(ops->fontbuffer); kfree(oldinfo->fbcon_par);
kfree(oldinfo->fbcon_par); oldinfo->fbcon_par = NULL;
oldinfo->fbcon_par = NULL; /*
module_put(oldinfo->fbops->owner); If oldinfo and newinfo are driving the same hardware,
/* the fb_release() method of oldinfo may attempt to
If oldinfo and newinfo are driving the same hardware, restore the hardware state. This will leave the
the fb_release() method of oldinfo may attempt to newinfo in an undefined state. Thus, a call to
restore the hardware state. This will leave the fb_set_par() may be needed for the newinfo.
newinfo in an undefined state. Thus, a call to */
fb_set_par() may be needed for the newinfo. if (newinfo && newinfo->fbops->fb_set_par) {
*/ ret = newinfo->fbops->fb_set_par(newinfo);
if (newinfo && newinfo->fbops->fb_set_par) {
ret = newinfo->fbops->fb_set_par(newinfo);
if (ret) if (ret)
printk(KERN_ERR "con2fb_release_oldinfo: " printk(KERN_ERR "con2fb_release_oldinfo: "
"detected unhandled fb_set_par error, " "detected unhandled fb_set_par error, "
"error code %d\n", ret); "error code %d\n", ret);
}
} }
return err; return 0;
} }
static void con2fb_init_display(struct vc_data *vc, struct fb_info *info, static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,
...@@ -919,7 +926,6 @@ static const char *fbcon_startup(void) ...@@ -919,7 +926,6 @@ static const char *fbcon_startup(void)
struct fbcon_display *p = &fb_display[fg_console]; struct fbcon_display *p = &fb_display[fg_console];
struct vc_data *vc = vc_cons[fg_console].d; struct vc_data *vc = vc_cons[fg_console].d;
const struct font_desc *font = NULL; const struct font_desc *font = NULL;
struct module *owner;
struct fb_info *info = NULL; struct fb_info *info = NULL;
struct fbcon_ops *ops; struct fbcon_ops *ops;
int rows, cols; int rows, cols;
...@@ -938,17 +944,12 @@ static const char *fbcon_startup(void) ...@@ -938,17 +944,12 @@ static const char *fbcon_startup(void)
if (!info) if (!info)
return NULL; return NULL;
owner = info->fbops->owner; if (fbcon_open(info))
if (!try_module_get(owner))
return NULL; return NULL;
if (info->fbops->fb_open && info->fbops->fb_open(info, 0)) {
module_put(owner);
return NULL;
}
ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
if (!ops) { if (!ops) {
module_put(owner); fbcon_release(info);
return NULL; return NULL;
} }
...@@ -3314,10 +3315,6 @@ static void fbcon_exit(void) ...@@ -3314,10 +3315,6 @@ static void fbcon_exit(void)
} }
if (mapped) { if (mapped) {
if (info->fbops->fb_release)
info->fbops->fb_release(info, 0);
module_put(info->fbops->owner);
if (info->fbcon_par) { if (info->fbcon_par) {
struct fbcon_ops *ops = info->fbcon_par; struct fbcon_ops *ops = info->fbcon_par;
...@@ -3327,6 +3324,8 @@ static void fbcon_exit(void) ...@@ -3327,6 +3324,8 @@ static void fbcon_exit(void)
kfree(info->fbcon_par); kfree(info->fbcon_par);
info->fbcon_par = NULL; info->fbcon_par = NULL;
} }
fbcon_release(info);
} }
} }
} }
......
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