[PATCH 3.14 57/83] tgafb: fix mode setting with fbset

Greg Kroah-Hartman
2014-05-11T19:41:21Z

From: Mikulas Patocka <mpatocka@redhat.com>

commit 624966589041deb32a2626ee2e176e8274581101 upstream.

Mode setting in the TGA driver is broken for these reasons:

- info->fix.line_length is set just once in tgafb_init_fix function. If
we change videomode, info->fix.line_length is not recalculated - so
the video mode is changed but the screen is corrupted because of wrong
info->fix.line_length.

- info->fix.smem_len is set in tgafb_init_fix to the size of the default
video mode (640x480). If we set a higher resolution,
info->fix.smem_len is smaller than the current screen size, preventing
the userspace program from mapping the framebuffer.

This patch fixes it:

- info->fix.line_length initialization is moved to tgafb_set_par so that
it is recalculated with each mode change.

- info->fix.smem_len is set to a fixed value representing the real
amount of video ram (the values are taken from xfree86 driver).

- add a check to tgafb_check_var to prevent us from setting a videomode
that doesn't fit into videoram.

- in tgafb_register, tgafb_init_fix is moved upwards, to be called
before fb_find_mode (because fb_find_mode already needs the videoram
size set in tgafb_init_fix).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/video/tgafb.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

--- a/drivers/video/tgafb.c
+++ b/drivers/video/tgafb.c
@@ -182,6 +182,8 @@ tgafb_check_var(struct fb_var_screeninfo

if (var->xres_virtual != var->xres || var->yres_virtual != var->yres)
return -EINVAL;
+ if (var->xres * var->yres * (var->bits_per_pixel >> 3) > info->fix.smem_len)
+ return -EINVAL;
if (var->nonstd)
return -EINVAL;
if (1000000000 / var->pixclock > TGA_PLL_MAX_FREQ)
@@ -262,6 +264,7 @@ tgafb_set_par(struct fb_info *info)
par->yres = info->var.yres;
par->pll_freq = pll_freq = 1000000000 / info->var.pixclock;
par->bits_per_pixel = info->var.bits_per_pixel;
+ info->fix.line_length = par->xres * (par->bits_per_pixel >> 3);

tga_type = par->tga_type;

@@ -1470,6 +1473,7 @@ tgafb_init_fix(struct fb_info *info)
int tga_bus_tc = TGA_BUS_TC(par->dev);
u8 tga_type = par->tga_type;
const char *tga_type_name = NULL;
+ unsigned memory_size;

switch (tga_type) {
case TGA_TYPE_8PLANE:
@@ -1477,22 +1481,27 @@ tgafb_init_fix(struct fb_info *info)
tga_type_name = "Digital ZLXp-E1";
if (tga_bus_tc)
tga_type_name = "Digital ZLX-E1";
+ memory_size = 2097152;
break;
case TGA_TYPE_24PLANE:
if (tga_bus_pci)
tga_type_name = "Digital ZLXp-E2";
if (tga_bus_tc)
tga_type_name = "Digital ZLX-E2";
+ memory_size = 8388608;
break;
case TGA_TYPE_24PLUSZ:
if (tga_bus_pci)
tga_type_name = "Digital ZLXp-E3";
if (tga_bus_tc)
tga_type_name = "Digital ZLX-E3";
+ memory_size = 16777216;
break;
}
- if (!tga_type_name)
+ if (!tga_type_name) {
tga_type_name = "Unknown";
+ memory_size = 16777216;
+ }

strlcpy(info->fix.id, tga_type_name, sizeof(info->fix.id));

@@ -1502,9 +1511,8 @@ tgafb_init_fix(struct fb_info *info)
? FB_VISUAL_PSEUDOCOLOR
: FB_VISUAL_DIRECTCOLOR);

- info->fix.line_length = par->xres * (par->bits_per_pixel >> 3);
info->fix.smem_start = (size_t) par->tga_fb_base;
- info->fix.smem_len = info->fix.line_length * par->yres;
+ info->fix.smem_len = memory_size;
info->fix.mmio_start = (size_t) par->tga_regs_base;
info->fix.mmio_len = 512;

@@ -1628,6 +1636,9 @@ static int tgafb_register(struct device
modedb_tga = &modedb_tc;
modedbsize_tga = 1;
}
+
+ tgafb_init_fix(info);
+
ret = fb_find_mode(&info->var, info,
mode_option ? mode_option : mode_option_tga,
modedb_tga, modedbsize_tga, NULL,
@@ -1645,7 +1656,6 @@ static int tgafb_register(struct device
}

tgafb_set_par(info);
- tgafb_init_fix(info);

if (register_framebuffer(info) < 0) {
printk(KERN_ERR "tgafb: Could not register framebuffer\n");