atmel_lcdfb: avoid division by zero
Avoid division by zero in atmel_lcdfb_check_var() function.
If pixclock is not specified while passing a var structure in
the check_var() funtion, a division by zero occurs (when
translating pixclock to KHz).
This patch adds a checking of this value and try to choose a
video mode in the modelist.
The mode found in the probe function in added to the modelist.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index d335bb9..5b3a15d 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -256,6 +256,20 @@
return 0;
}
+static const struct fb_videomode *atmel_lcdfb_choose_mode(struct fb_var_screeninfo *var,
+ struct fb_info *info)
+{
+ struct fb_videomode varfbmode;
+ const struct fb_videomode *fbmode = NULL;
+
+ fb_var_to_videomode(&varfbmode, var);
+ fbmode = fb_find_nearest_mode(&varfbmode, &info->modelist);
+ if (fbmode)
+ fb_videomode_to_var(var, fbmode);
+ return fbmode;
+}
+
+
/**
* atmel_lcdfb_check_var - Validates a var passed in.
* @var: frame buffer variable screen structure
@@ -289,6 +303,15 @@
clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;
dev_dbg(dev, "%s:\n", __func__);
+
+ if (!(var->pixclock && var->bits_per_pixel)) {
+ /* choose a suitable mode if possible */
+ if (!atmel_lcdfb_choose_mode(var, info)) {
+ dev_err(dev, "needed value not specified\n");
+ return -EINVAL;
+ }
+ }
+
dev_dbg(dev, " resolution: %ux%u\n", var->xres, var->yres);
dev_dbg(dev, " pixclk: %lu KHz\n", PICOS2KHZ(var->pixclock));
dev_dbg(dev, " bpp: %u\n", var->bits_per_pixel);
@@ -299,6 +322,13 @@
return -EINVAL;
}
+ /* Do not allow to have real resoulution larger than virtual */
+ if (var->xres > var->xres_virtual)
+ var->xres_virtual = var->xres;
+
+ if (var->yres > var->yres_virtual)
+ var->yres_virtual = var->yres;
+
/* Force same alignment for each line */
var->xres = (var->xres + 3) & ~3UL;
var->xres_virtual = (var->xres_virtual + 3) & ~3UL;
@@ -740,6 +770,7 @@
struct fb_info *info;
struct atmel_lcdfb_info *sinfo;
struct atmel_lcdfb_info *pdata_sinfo;
+ struct fb_videomode fbmode;
struct resource *regs = NULL;
struct resource *map = NULL;
int ret;
@@ -906,6 +937,10 @@
goto free_cmap;
}
+ /* add selected videomode to modelist */
+ fb_var_to_videomode(&fbmode, &info->var);
+ fb_add_videomode(&fbmode, &info->modelist);
+
/* Power up the LCDC screen */
if (sinfo->atmel_lcdfb_power_control)
sinfo->atmel_lcdfb_power_control(1);