From 2a2483072393b27f4336ab068a1f48ca19ff1c1e Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Thu, 24 Jan 2013 14:14:19 +1000 Subject: vgacon/vt: clear buffer attributes when we load a 512 character font (v2) When we switch from 256->512 byte font rendering mode, it means the current contents of the screen is being reinterpreted. The bit that holds the high bit of the 9-bit font, may have been previously set, and thus the new font misrenders. The problem case we see is grub2 writes spaces with the bit set, so it ends up with data like 0x820, which gets reinterpreted into 0x120 char which the font translates into G with a circumflex. This flashes up on screen at boot and is quite ugly. A current side effect of this patch though is that any rendering on the screen changes color to a slightly darker color, but at least the screen no longer corrupts. v2: as suggested by hpa, always clear the attribute space, whether we are are going to or from 512 chars. Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie --- drivers/video/console/vgacon.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'drivers/video/console') diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index d449a74d4a31..5855d17d19ac 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -1064,7 +1064,7 @@ static int vgacon_do_font_op(struct vgastate *state,char *arg,int set,int ch512) unsigned short video_port_status = vga_video_port_reg + 6; int font_select = 0x00, beg, i; char *charmap; - + bool clear_attribs = false; if (vga_video_type != VIDEO_TYPE_EGAM) { charmap = (char *) VGA_MAP_MEM(colourmap, 0); beg = 0x0e; @@ -1169,12 +1169,6 @@ static int vgacon_do_font_op(struct vgastate *state,char *arg,int set,int ch512) /* if 512 char mode is already enabled don't re-enable it. */ if ((set) && (ch512 != vga_512_chars)) { - /* attribute controller */ - for (i = 0; i < MAX_NR_CONSOLES; i++) { - struct vc_data *c = vc_cons[i].d; - if (c && c->vc_sw == &vga_con) - c->vc_hi_font_mask = ch512 ? 0x0800 : 0; - } vga_512_chars = ch512; /* 256-char: enable intensity bit 512-char: disable intensity bit */ @@ -1185,8 +1179,22 @@ static int vgacon_do_font_op(struct vgastate *state,char *arg,int set,int ch512) it means, but it works, and it appears necessary */ inb_p(video_port_status); vga_wattr(state->vgabase, VGA_AR_ENABLE_DISPLAY, 0); + clear_attribs = true; } raw_spin_unlock_irq(&vga_lock); + + if (clear_attribs) { + for (i = 0; i < MAX_NR_CONSOLES; i++) { + struct vc_data *c = vc_cons[i].d; + if (c && c->vc_sw == &vga_con) { + /* force hi font mask to 0, so we always clear + the bit on either transition */ + c->vc_hi_font_mask = 0x00; + clear_buffer_attributes(c); + c->vc_hi_font_mask = ch512 ? 0x0800 : 0; + } + } + } return 0; } -- cgit v1.2.1 From ae1287865f5361fa138d4d3b1b6277908b54eac9 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Thu, 24 Jan 2013 16:12:41 +1000 Subject: fbcon: don't lose the console font across generic->chip driver switch If grub2 loads efifb/vesafb, then when systemd starts it can set the console font on that framebuffer device, however when we then load the native KMS driver, the first thing it does is tear down the generic framebuffer driver. The thing is the generic code is doing the right thing, it frees the font because otherwise it would leak memory. However we can assume that if you are removing the generic firmware driver (vesa/efi/offb), that a new driver *should* be loading soon after, so we effectively leak the font. However the old code left a dangling pointer in vc->vc_font.data and we can now reuse that dangling pointer to load the font into the new driver, now that we aren't freeing it. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=892340 Cc: Kay Sievers Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie --- drivers/video/console/fbcon.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'drivers/video/console') diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index fdefa8fd72c4..f8dbe76a1b6f 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -990,7 +990,7 @@ static const char *fbcon_startup(void) } /* Setup default font */ - if (!p->fontdata) { + if (!p->fontdata && !vc->vc_font.data) { if (!fontname[0] || !(font = find_font(fontname))) font = get_default_font(info->var.xres, info->var.yres, @@ -1000,6 +1000,8 @@ static const char *fbcon_startup(void) vc->vc_font.height = font->height; vc->vc_font.data = (void *)(p->fontdata = font->data); vc->vc_font.charcount = 256; /* FIXME Need to support more fonts */ + } else { + p->fontdata = vc->vc_font.data; } cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres); @@ -1159,9 +1161,9 @@ static void fbcon_init(struct vc_data *vc, int init) ops->p = &fb_display[fg_console]; } -static void fbcon_free_font(struct display *p) +static void fbcon_free_font(struct display *p, bool freefont) { - if (p->userfont && p->fontdata && (--REFCOUNT(p->fontdata) == 0)) + if (freefont && p->userfont && p->fontdata && (--REFCOUNT(p->fontdata) == 0)) kfree(p->fontdata - FONT_EXTRA_WORDS * sizeof(int)); p->fontdata = NULL; p->userfont = 0; @@ -1173,8 +1175,8 @@ static void fbcon_deinit(struct vc_data *vc) struct fb_info *info; struct fbcon_ops *ops; int idx; + bool free_font = true; - fbcon_free_font(p); idx = con2fb_map[vc->vc_num]; if (idx == -1) @@ -1185,6 +1187,8 @@ static void fbcon_deinit(struct vc_data *vc) if (!info) goto finished; + if (info->flags & FBINFO_MISC_FIRMWARE) + free_font = false; ops = info->fbcon_par; if (!ops) @@ -1196,6 +1200,8 @@ static void fbcon_deinit(struct vc_data *vc) ops->flags &= ~FBCON_FLAGS_INIT; finished: + fbcon_free_font(p, free_font); + if (!con_is_bound(&fb_con)) fbcon_exit(); -- cgit v1.2.1