Commit 3b0fb6ab authored by Daniel Vetter's avatar Daniel Vetter
Browse files

fbcon: Use delayed work for cursor 



Allows us to delete a bunch of hand-rolled stuff using a timer plus a
separate work). Also to simplify the code we initialize the
cursor_work completely when we allocate the fbcon_ops structure,
instead of trying to cope with console re-initialization.

The motiviation here is that fbcon code stops using the fb_info.queue,
which helps with locking issues around cleanup and all that in a later
patch.

Also note that this allows us to ditch the hand-rolled work cleanup in
fbcon_exit - we already call fbcon_del_cursor_timer, which takes care
of everything. Plus this was racy anyway.

v2:
- Only INIT_DELAYED_WORK when kzalloc succeeded (Tetsuo)
- Explain that we replace both the timer and a work with the combined
  delayed_work (Javier)

Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Acked-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-7-daniel.vetter@ffwll.ch
parent 9ad5cc9b

drivers/video/fbdev/core/fbcon.c

+33 −52
Original line number Diff line number Diff line
@@ -350,8 +350,8 @@ static int get_color(struct vc_data *vc, struct fb_info *info, 


static void fb_flashcursor(struct work_struct *work)

{

	struct fb_info *info = container_of(work, struct fb_info, queue);

	struct fbcon_ops *ops = info->fbcon_par;

	struct fbcon_ops *ops = container_of(work, struct fbcon_ops, cursor_work.work);

	struct fb_info *info;

	struct vc_data *vc = NULL;

	int c;

	int mode;
@@ -364,7 +364,10 @@ static void fb_flashcursor(struct work_struct *work) 
	if (ret == 0)

		return;



	if (ops && ops->currcon != -1)

	/* protected by console_lock */

	info = ops->info;



	if (ops->currcon != -1)

		vc = vc_cons[ops->currcon].d;



	if (!vc || !con_is_visible(vc) ||
@@ -380,42 +383,25 @@ static void fb_flashcursor(struct work_struct *work) 
	ops->cursor(vc, info, mode, get_color(vc, info, c, 1),

		    get_color(vc, info, c, 0));

	console_unlock();

}



static void cursor_timer_handler(struct timer_list *t)

{

	struct fbcon_ops *ops = from_timer(ops, t, cursor_timer);

	struct fb_info *info = ops->info;



	queue_work(system_power_efficient_wq, &info->queue);

	mod_timer(&ops->cursor_timer, jiffies + ops->cur_blink_jiffies);

	queue_delayed_work(system_power_efficient_wq, &ops->cursor_work,

			   ops->cur_blink_jiffies);

}



static void fbcon_add_cursor_timer(struct fb_info *info)

static void fbcon_add_cursor_work(struct fb_info *info)

{

	struct fbcon_ops *ops = info->fbcon_par;



	if ((!info->queue.func || info->queue.func == fb_flashcursor) &&

	    !(ops->flags & FBCON_FLAGS_CURSOR_TIMER) &&

	    !fbcon_cursor_noblink) {

		if (!info->queue.func)

			INIT_WORK(&info->queue, fb_flashcursor);



		timer_setup(&ops->cursor_timer, cursor_timer_handler, 0);

		mod_timer(&ops->cursor_timer, jiffies + ops->cur_blink_jiffies);

		ops->flags |= FBCON_FLAGS_CURSOR_TIMER;

	}

	if (!fbcon_cursor_noblink)

		queue_delayed_work(system_power_efficient_wq, &ops->cursor_work,

				   ops->cur_blink_jiffies);

}



static void fbcon_del_cursor_timer(struct fb_info *info)

static void fbcon_del_cursor_work(struct fb_info *info)

{

	struct fbcon_ops *ops = info->fbcon_par;



	if (info->queue.func == fb_flashcursor &&

	    ops->flags & FBCON_FLAGS_CURSOR_TIMER) {

		del_timer_sync(&ops->cursor_timer);

		ops->flags &= ~FBCON_FLAGS_CURSOR_TIMER;

	}

	cancel_delayed_work_sync(&ops->cursor_work);

}



#ifndef MODULE
@@ -717,6 +703,8 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, 
	}



	if (!err) {

		INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);



		ops->cur_blink_jiffies = HZ / 5;

		ops->info = info;

		info->fbcon_par = ops;
@@ -751,7 +739,7 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, 
	}



	if (!err) {

		fbcon_del_cursor_timer(oldinfo);

		fbcon_del_cursor_work(oldinfo);

		kfree(ops->cursor_state.mask);

		kfree(ops->cursor_data);

		kfree(ops->cursor_src);
@@ -867,7 +855,7 @@ static int set_con2fb_map(int unit, int newidx, int user) 
				 logo_shown != FBCON_LOGO_DONTSHOW);



		if (!found)

			fbcon_add_cursor_timer(info);

			fbcon_add_cursor_work(info);

		con2fb_map_boot[unit] = newidx;

		con2fb_init_display(vc, info, unit, show_logo);

	}
@@ -964,6 +952,8 @@ static const char *fbcon_startup(void) 
		return NULL;

	}



	INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor);



	ops->currcon = -1;

	ops->graphics = 1;

	ops->cur_rotate = -1;
@@ -1006,7 +996,7 @@ static const char *fbcon_startup(void) 
		 info->var.yres,

		 info->var.bits_per_pixel);



	fbcon_add_cursor_timer(info);

	fbcon_add_cursor_work(info);

	return display_desc;

}
@@ -1194,7 +1184,7 @@ static void fbcon_deinit(struct vc_data *vc) 
		goto finished;



	if (con_is_visible(vc))

		fbcon_del_cursor_timer(info);

		fbcon_del_cursor_work(info);



	ops->flags &= ~FBCON_FLAGS_INIT;

finished:
@@ -1320,9 +1310,9 @@ static void fbcon_cursor(struct vc_data *vc, int mode) 
		return;



	if (vc->vc_cursor_type & CUR_SW)

		fbcon_del_cursor_timer(info);

		fbcon_del_cursor_work(info);

	else

		fbcon_add_cursor_timer(info);

		fbcon_add_cursor_work(info);



	ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;
@@ -2132,14 +2122,14 @@ static int fbcon_switch(struct vc_data *vc) 
		}



		if (old_info != info)

			fbcon_del_cursor_timer(old_info);

			fbcon_del_cursor_work(old_info);

	}



	if (fbcon_is_inactive(vc, info) ||

	    ops->blank_state != FB_BLANK_UNBLANK)

		fbcon_del_cursor_timer(info);

		fbcon_del_cursor_work(info);

	else

		fbcon_add_cursor_timer(info);

		fbcon_add_cursor_work(info);



	set_blitting_type(vc, info);

	ops->cursor_reset = 1;
@@ -2247,9 +2237,9 @@ static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch) 


	if (mode_switch || fbcon_is_inactive(vc, info) ||

	    ops->blank_state != FB_BLANK_UNBLANK)

		fbcon_del_cursor_timer(info);

		fbcon_del_cursor_work(info);

	else

		fbcon_add_cursor_timer(info);

		fbcon_add_cursor_work(info);



	return 0;

}
@@ -3181,7 +3171,7 @@ static ssize_t show_cursor_blink(struct device *device, 
	if (!ops)

		goto err;



	blink = (ops->flags & FBCON_FLAGS_CURSOR_TIMER) ? 1 : 0;

	blink = delayed_work_pending(&ops->cursor_work);

err:

	console_unlock();

	return snprintf(buf, PAGE_SIZE, "%d\n", blink);
@@ -3210,10 +3200,10 @@ static ssize_t store_cursor_blink(struct device *device, 


	if (blink) {

		fbcon_cursor_noblink = 0;

		fbcon_add_cursor_timer(info);

		fbcon_add_cursor_work(info);

	} else {

		fbcon_cursor_noblink = 1;

		fbcon_del_cursor_timer(info);

		fbcon_del_cursor_work(info);

	}



err:
@@ -3314,15 +3304,9 @@ static void fbcon_exit(void) 
#endif



	for_each_registered_fb(i) {

		int pending = 0;



		mapped = 0;

		info = registered_fb[i];



		if (info->queue.func)

			pending = cancel_work_sync(&info->queue);

		pr_debug("fbcon: %s pending work\n", (pending ? "canceled" : "no"));



		for (j = first_fb_vc; j <= last_fb_vc; j++) {

			if (con2fb_map[j] == i) {

				mapped = 1;
@@ -3338,15 +3322,12 @@ static void fbcon_exit(void) 
			if (info->fbcon_par) {

				struct fbcon_ops *ops = info->fbcon_par;



				fbcon_del_cursor_timer(info);

				fbcon_del_cursor_work(info);

				kfree(ops->cursor_src);

				kfree(ops->cursor_state.mask);

				kfree(info->fbcon_par);

				info->fbcon_par = NULL;

			}



			if (info->queue.func == fb_flashcursor)

				info->queue.func = NULL;

		}

	}

}

drivers/video/fbdev/core/fbcon.h

+2 −2
Original line number Diff line number Diff line
@@ -14,11 +14,11 @@ 
#include <linux/types.h>

#include <linux/vt_buffer.h>

#include <linux/vt_kern.h>

#include <linux/workqueue.h>



#include <asm/io.h>



#define FBCON_FLAGS_INIT         1

#define FBCON_FLAGS_CURSOR_TIMER 2



   /*

    *    This is the interface between the low-level console driver and the
@@ -68,7 +68,7 @@ struct fbcon_ops { 
	int  (*update_start)(struct fb_info *info);

	int  (*rotate_font)(struct fb_info *info, struct vc_data *vc);

	struct fb_var_screeninfo var;  /* copy of the current fb_var_screeninfo */

	struct timer_list cursor_timer; /* Cursor timer */

	struct delayed_work cursor_work; /* Cursor timer */

	struct fb_cursor cursor_state;

	struct fbcon_display *p;

	struct fb_info *info;