From 0f2893f0d1acff4bb1677b60c0486adc0075cb99 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 13 May 2014 12:09:27 +0200 Subject: [PATCH] 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: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- drivers/video/console/vgacon.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 9d8feac67637..9e18770aaba6 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -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);