[PATCH] fbdev: Speed up scrolling of tdfxfb

This patch speeds up scrolling of tdfxfb by maximizing var->yres_virtual so
tdfxfb uses SCROLL_PAN_MOVE instead of SCROLL_REDRAW.  This is true whether
CONFIG_FB_3DFX_ACCEL is set or not.  This problem was reported by Paolo
Ornati <ornati@fastwebnet.it> who also made substantial contributions to
solve this problem.

This patch also fixes compile errors when CONFIG_FB_3DFX_ACCEL is false.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/video/tdfxfb.c b/drivers/video/tdfxfb.c
index b58eced6d6b7465b4127db5fe818f2fd9f7fbd26..5aa485de58e88380727b560be5ecce7db9a17fb0 100644 (file)
--- a/drivers/video/tdfxfb.c
+++ b/drivers/video/tdfxfb.c
@@ -168,7 +168,6 @@ static int banshee_wait_idle(struct fb_info *info);
 static void tdfxfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect);
 static void tdfxfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);  
 static void tdfxfb_imageblit(struct fb_info *info, const struct fb_image *image); 
-static int tdfxfb_cursor(struct fb_info *info, struct fb_cursor *cursor);
 #endif /* CONFIG_FB_3DFX_ACCEL */
 
 static struct fb_ops tdfxfb_ops = {
@@ -183,13 +182,12 @@ static struct fb_ops tdfxfb_ops = {
        .fb_fillrect    = tdfxfb_fillrect,
        .fb_copyarea    = tdfxfb_copyarea,
        .fb_imageblit   = tdfxfb_imageblit,
-       .fb_cursor      = tdfxfb_cursor,
 #else
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
-       .fb_cursor      = soft_cursor,
 #endif
+       .fb_cursor      = soft_cursor,
 };
 
 /*
@@ -502,15 +500,11 @@ static int tdfxfb_check_var(struct fb_var_screeninfo *var,struct fb_info *info)
                return -EINVAL;
        }
 
-       if (var->xres != var->xres_virtual) {
-               DPRINTK("virtual x resolution != physical x resolution not supported\n");
-               return -EINVAL;
-       }
+       if (var->xres != var->xres_virtual)
+               var->xres_virtual = var->xres;
 
-       if (var->yres > var->yres_virtual) {
-               DPRINTK("virtual y resolution < physical y resolution not possible\n");
-               return -EINVAL;
-       }
+       if (var->yres > var->yres_virtual)
+               var->yres_virtual = var->yres;
 
        if (var->xoffset) {
                DPRINTK("xoffset not supported\n");
@@ -539,9 +533,12 @@ static int tdfxfb_check_var(struct fb_var_screeninfo *var,struct fb_info *info)
        }
   
        if (lpitch * var->yres_virtual > info->fix.smem_len) {
-               DPRINTK("no memory for screen (%ux%ux%u)\n",
-               var->xres, var->yres_virtual, var->bits_per_pixel);
-               return -EINVAL;
+               var->yres_virtual = info->fix.smem_len/lpitch;
+               if (var->yres_virtual < var->yres) {
+                       DPRINTK("no memory for screen (%ux%ux%u)\n",
+                       var->xres, var->yres_virtual, var->bits_per_pixel);
+                       return -EINVAL;
+               }
        }
   
        if (PICOS2KHZ(var->pixclock) > par->max_pixclock) {
@@ -1030,7 +1027,9 @@ static void tdfxfb_imageblit(struct fb_info *info, const struct fb_image *image)
        }
        banshee_wait_idle(info);
 }
+#endif /* CONFIG_FB_3DFX_ACCEL */
 
+#ifdef TDFX_HARDWARE_CURSOR
 static int tdfxfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
 {
        struct tdfx_par *par = (struct tdfx_par *) info->par;
@@ -1167,7 +1166,7 @@ static int tdfxfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
        spin_unlock_irqrestore(&par->DAClock, flags);
        return 0;
 }
-#endif /* CONFIG_FB_3DFX_ACCEL */
+#endif
 
 /**
  *      tdfxfb_probe - Device Initializiation
@@ -1183,7 +1182,7 @@ static int __devinit tdfxfb_probe(struct pci_dev *pdev,
 {
        struct tdfx_par *default_par;
        struct fb_info *info;
-       int size, err;
+       int size, err, lpitch;
 
        if ((err = pci_enable_device(pdev))) {
                printk(KERN_WARNING "tdfxfb: Can't enable pdev: %d\n", err);
@@ -1288,6 +1287,22 @@ static int __devinit tdfxfb_probe(struct pci_dev *pdev,
        if (!err || err == 4)
                info->var = tdfx_var;
 
+       /* maximize virtual vertical length */
+       lpitch = info->var.xres_virtual * ((info->var.bits_per_pixel + 7) >> 3);
+       info->var.yres_virtual = info->fix.smem_len/lpitch;
+       if (info->var.yres_virtual < info->var.yres)
+               goto out_err;
+
+#ifdef CONFIG_FB_3DFX_ACCEL
+       /*
+        * FIXME: Limit var->yres_virtual to 4096 because of screen artifacts
+        * during scrolling. This is only present if 2D acceleration is
+        * enabled.
+        */
+       if (info->var.yres_virtual > 4096)
+               info->var.yres_virtual = 4096;
+#endif /* CONFIG_FB_3DFX_ACCEL */
+
        if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
                printk(KERN_WARNING "tdfxfb: Can't allocate color map\n");
                goto out_err;