OMAP: DSS2: OMAPFB: Reduce stack usage

omapfb_mode_to_timings() had struct fb_info, struct fb_var and struct
fb_ops allocated from stack. This caused the stack usage grow quite
high.

Use kzalloc to allocate the structs instead.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 61 insertions, 34 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb-main.c b/drivers/video/omap2/omapfb/omapfb-main.c
index 9a5b4bc81c80..505bc12a3031 100644
--- a/drivers/video/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/omap2/omapfb/omapfb-main.c
@@ -1996,9 +1996,9 @@ static int omapfb_create_framebuffers(struct omapfb2_device *fbdev)
 static int omapfb_mode_to_timings(const char *mode_str,
                 struct omap_video_timings *timings, u8 *bpp)
 {
-        struct fb_info fbi;
-        struct fb_var_screeninfo var;
-        struct fb_ops fbops;
+        struct fb_info *fbi;
+        struct fb_var_screeninfo *var;
+        struct fb_ops *fbops;
         int r;
 
 #ifdef CONFIG_OMAP2_DSS_VENC
@@ -2016,39 +2016,66 @@ static int omapfb_mode_to_timings(const char *mode_str,
         /* this is quite a hack, but I wanted to use the modedb and for
          * that we need fb_info and var, so we create dummy ones */
 
-        memset(&fbi, 0, sizeof(fbi));
-        memset(&var, 0, sizeof(var));
-        memset(&fbops, 0, sizeof(fbops));
-        fbi.fbops = &fbops;
-
-        r = fb_find_mode(&var, &fbi, mode_str, NULL, 0, NULL, 24);
-
-        if (r != 0) {
-                timings->pixel_clock = PICOS2KHZ(var.pixclock);
-                timings->hbp = var.left_margin;
-                timings->hfp = var.right_margin;
-                timings->vbp = var.upper_margin;
-                timings->vfp = var.lower_margin;
-                timings->hsw = var.hsync_len;
-                timings->vsw = var.vsync_len;
-                timings->x_res = var.xres;
-                timings->y_res = var.yres;
-
-                switch (var.bits_per_pixel) {
-                case 16:
-                        *bpp = 16;
-                        break;
-                case 24:
-                case 32:
-                default:
-                        *bpp = 24;
-                        break;
-                }
+        *bpp = 0;
+        fbi = NULL;
+        var = NULL;
+        fbops = NULL;
 
-                return 0;
-        } else {
-                return -EINVAL;
+        fbi = kzalloc(sizeof(*fbi), GFP_KERNEL);
+        if (fbi == NULL) {
+                r = -ENOMEM;
+                goto err;
+        }
+
+        var = kzalloc(sizeof(*var), GFP_KERNEL);
+        if (var == NULL) {
+                r = -ENOMEM;
+                goto err;
+        }
+
+        fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
+        if (fbops == NULL) {
+                r = -ENOMEM;
+                goto err;
+        }
+
+        fbi->fbops = fbops;
+
+        r = fb_find_mode(var, fbi, mode_str, NULL, 0, NULL, 24);
+        if (r == 0) {
+                r = -EINVAL;
+                goto err;
         }
+
+        timings->pixel_clock = PICOS2KHZ(var->pixclock);
+        timings->hbp = var->left_margin;
+        timings->hfp = var->right_margin;
+        timings->vbp = var->upper_margin;
+        timings->vfp = var->lower_margin;
+        timings->hsw = var->hsync_len;
+        timings->vsw = var->vsync_len;
+        timings->x_res = var->xres;
+        timings->y_res = var->yres;
+
+        switch (var->bits_per_pixel) {
+        case 16:
+                *bpp = 16;
+                break;
+        case 24:
+        case 32:
+        default:
+                *bpp = 24;
+                break;
+        }
+
+        r = 0;
+
+err:
+        kfree(fbi);
+        kfree(var);
+        kfree(fbops);
+
+        return r;
 }
 
 static int omapfb_set_def_mode(struct omapfb2_device *fbdev,