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HID: picolcd: do not reallocate memory on depth change

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Reallocating memory in depth change does not work well if some
userspace application has mmapped() the framebuffer as that mapping
does not get adjusted (thus application continues to write to old
buffer).
In addition doing deferred_io_cleanup() and init() inside of set_par()
tends to deadlock with fbcon's flashing cursor.

Avoid all this by allocating a buffer that can hold 8bpp framebuffer
and just use 1/8 of it while running at 1bpp.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Bruno Prémont 2010-06-28 22:31:20 +02:00 committed by Jiri Kosina
parent b70884ff3a
commit 365f1fcd0d
1 changed files with 12 additions and 15 deletions
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27
drivers/hid/hid-picolcd.c
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@ -563,19 +563,18 @@ static int picolcd_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *i
static int picolcd_set_par(struct fb_info *info)
{
struct picolcd_data *data = info->par;
u8 *o_fb, *n_fb;
u8 *tmp_fb, *o_fb;
if (info->var.bits_per_pixel == data->fb_bpp)
return 0;
/* switch between 1/8 bit depths */
if (info->var.bits_per_pixel != 1 && info->var.bits_per_pixel != 8)
return -EINVAL;
o_fb = data->fb_bitmap;
n_fb = vmalloc(PICOLCDFB_SIZE*info->var.bits_per_pixel);
if (!n_fb)
o_fb = data->fb_bitmap;
tmp_fb = kmalloc(PICOLCDFB_SIZE*info->var.bits_per_pixel, GFP_KERNEL);
if (!tmp_fb)
return -ENOMEM;
fb_deferred_io_cleanup(info);
/* translate FB content to new bits-per-pixel */
if (info->var.bits_per_pixel == 1) {
int i, b;
@ -585,24 +584,22 @@ static int picolcd_set_par(struct fb_info *info)
p <<= 1;
p |= o_fb[i*8+b] ? 0x01 : 0x00;
}
tmp_fb[i] = p;
}
memcpy(o_fb, tmp_fb, PICOLCDFB_SIZE);
info->fix.visual = FB_VISUAL_MONO01;
info->fix.line_length = PICOLCDFB_WIDTH / 8;
} else {
int i;
memcpy(tmp_fb, o_fb, PICOLCDFB_SIZE);
for (i = 0; i < PICOLCDFB_SIZE * 8; i++)
n_fb[i] = o_fb[i/8] & (0x01 << (7 - i % 8)) ? 0xff : 0x00;
info->fix.visual = FB_VISUAL_TRUECOLOR;
o_fb[i] = tmp_fb[i/8] & (0x01 << (7 - i % 8)) ? 0xff : 0x00;
info->fix.visual = FB_VISUAL_DIRECTCOLOR;
info->fix.line_length = PICOLCDFB_WIDTH;
}
data->fb_bitmap = n_fb;
kfree(tmp_fb);
data->fb_bpp = info->var.bits_per_pixel;
info->screen_base = (char __force __iomem *)n_fb;
info->fix.smem_start = (unsigned long)n_fb;
info->fix.smem_len = PICOLCDFB_SIZE*data->fb_bpp;
fb_deferred_io_init(info);
vfree(o_fb);
return 0;
}
@ -692,7 +689,7 @@ static int picolcd_init_framebuffer(struct picolcd_data *data)
u8 *fb_bitmap = NULL;
u32 *palette;
fb_bitmap = vmalloc(PICOLCDFB_SIZE*picolcdfb_var.bits_per_pixel);
fb_bitmap = vmalloc(PICOLCDFB_SIZE*8);
if (fb_bitmap == NULL) {
dev_err(dev, "can't get a free page for framebuffer\n");
goto err_nomem;
@ -728,7 +725,7 @@ static int picolcd_init_framebuffer(struct picolcd_data *data)
info->fbops = &picolcdfb_ops;
info->var = picolcdfb_var;
info->fix = picolcdfb_fix;
info->fix.smem_len = PICOLCDFB_SIZE;
info->fix.smem_len = PICOLCDFB_SIZE*8;
info->fix.smem_start = (unsigned long)fb_bitmap;
info->par = data;
info->flags = FBINFO_FLAG_DEFAULT;