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Commit 0f2893f0 authored by Takashi Iwai's avatar Takashi Iwai Committed by Greg Kroah-Hartman
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vgacon: Fix & cleanup refcounting 



The vgacon driver prepares a two element array of uni_pagedir_loc and
uses the second item as its own reference counter for sharing the
uni_pagedir.  And the code assumes blindly that the second item is
available if the assigned vc_uni_pagedir isn't the standard one, which
might be wrong (although currently it's so).

This patch fixes that wrong assumption, and gives a slight cleanup
along with it: namely, instead of array, just give the uni_pagedir_loc
and a separate refcount variable.  It makes the code a bit more
understandable at first glance.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4061f498

drivers/video/console/vgacon.c

+8 −7
Original line number Diff line number Diff line
@@ -87,7 +87,8 @@ static void vgacon_save_screen(struct vc_data *c); 
static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,

			 int lines);

static void vgacon_invert_region(struct vc_data *c, u16 * p, int count);

static unsigned long vgacon_uni_pagedir[2];

static unsigned long vgacon_uni_pagedir;

static int vgacon_refcount;



/* Description of the hardware situation */

static int		vga_init_done		__read_mostly;
@@ -575,12 +576,12 @@ static void vgacon_init(struct vc_data *c, int init) 
	if (vga_512_chars)

		c->vc_hi_font_mask = 0x0800;

	p = *c->vc_uni_pagedir_loc;

	if (c->vc_uni_pagedir_loc == &c->vc_uni_pagedir ||

	    !--c->vc_uni_pagedir_loc[1])

	if (c->vc_uni_pagedir_loc != &vgacon_uni_pagedir) {

		con_free_unimap(c);

	c->vc_uni_pagedir_loc = vgacon_uni_pagedir;

	vgacon_uni_pagedir[1]++;

	if (!vgacon_uni_pagedir[0] && p)

		c->vc_uni_pagedir_loc = &vgacon_uni_pagedir;

		vgacon_refcount++;

	}

	if (!vgacon_uni_pagedir && p)

		con_set_default_unimap(c);



	/* Only set the default if the user didn't deliberately override it */
@@ -597,7 +598,7 @@ static void vgacon_deinit(struct vc_data *c) 
		vga_set_mem_top(c);

	}



	if (!--vgacon_uni_pagedir[1])

	if (!--vgacon_refcount)

		con_free_unimap(c);

	c->vc_uni_pagedir_loc = &c->vc_uni_pagedir;

	con_set_default_unimap(c);