Skip to contentSkip to conversation

fbdev: Batch cmap changes at driver level

PATCH In review Benjamin Herrenschmidt 2 participants 2 messages Apr 10, 2005 – May 2, 2005 Framebuffer layer

lore
Share & tools
lore

Benjamin Herrenschmidt

author
#0 lore raw

PATCH 1/1 fbdev: Batch cmap changes at driver level

Hi ! Andrew, if Tony ack's it, please push that upstream.

This patch adds to the fbdev interface a set_cmap callback that allow the driver to "batch" palette changes. This is useful for drivers like radeonfb which might require lenghtly workarounds on palette accesses, thus allowing to factor out those workarounds efficiently.

Signed-off-by Benjamin Herrenschmidt <[email protected]>
include/linux/fb.h +3 -0
Index: linux-work/include/linux/fb.h
===================================================================
@@ -563,6 +563,9 @@
 	int (*fb_setcolreg)(unsigned regno, unsigned red, unsigned green,
 			    unsigned blue, unsigned transp, struct fb_info *info);
 
+	/* set color registers in batch */
+	int (*fb_setcmap)(struct fb_cmap *cmap, struct fb_info *info);
+
 	/* blank display */
 	int (*fb_blank)(int blank, struct fb_info *info);
drivers/video/aty/radeon_base.c +94 -24

163 lines not on this page · raw message

drivers/video/fbcmap.c +31 -3
Index: linux-work/drivers/video/fbcmap.c
===================================================================
@@ -222,8 +222,11 @@
 	transp = cmap->transp;
 	start = cmap->start;
 
-	if (start < 0 || !info->fbops->fb_setcolreg)
+	if (start < 0 || (!info->fbops->fb_setcolreg &&
+			  !info->fbops->fb_setcmap))
 		return -EINVAL;
+	if (info->fbops->fb_setcmap)
+		return info->fbops->fb_setcmap(cmap, info);
 	for (i = 0; i < cmap->len; i++) {
 		hred = *red++;
 		hgreen = *green++;

@@ -243,15 +246,40 @@
 	int i, start;
 	u16 __user *red, *green, *blue, *transp;
 	u_int hred, hgreen, hblue, htransp = 0xffff;
-
+	
 	red = cmap->red;
 	green = cmap->green;
 	blue = cmap->blue;
 	transp = cmap->transp;
 	start = cmap->start;
 
-	if (start < 0 || !info->fbops->fb_setcolreg)
+	if (start < 0 || (!info->fbops->fb_setcolreg &&
+			  !info->fbops->fb_setcmap))
 		return -EINVAL;
+	
+	/* If we can batch, do it */
+	if (info->fbops->fb_setcmap && cmap->len > 1) {
+		struct fb_cmap umap;
+		int size = cmap->len * sizeof(u16);
+		int rc;
+
+		memset(&umap, 0, sizeof(struct fb_cmap));
+		rc = fb_alloc_cmap(&umap, cmap->len, transp != NULL);
+		if (rc)
+			return rc;
+		if (copy_from_user(umap.red, red, size) ||
+		    copy_from_user(umap.green, green, size) ||
+		    copy_from_user(umap.blue, blue, size) ||
+		    (transp && copy_from_user(umap.transp, transp, size))) {
+			rc = -EFAULT;
+		}
+		umap.start = start;
+		if (rc == 0)
+			rc = info->fbops->fb_setcmap(&umap, info);
+		fb_dealloc_cmap(&umap);
+		return rc;
+	}
+
 	for (i = 0; i < cmap->len; i++, red++, blue++, green++) {
 		if (get_user(hred, red) ||
 		    get_user(hgreen, green) ||

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Linux-fbdev-devel mailing list [email protected]
https://lists.sourceforge.net/lists/listinfo/linux-fbdev-devel

Signature · 9 lines
Benjamin Herrenschmidt <[email protected]>



-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
#1 lore raw

include/linux/fb.h line 570

Quoted 11 lines

This patch adds to the fbdev interface a set_cmap callback that allow the driver to "batch" palette changes. This is useful for drivers like radeonfb which might require lenghtly workarounds on palette accesses, thus allowing to factor out those workarounds efficiently.

include/linux/fb.h +3 -0
+	/* set color registers in batch */
+	int (*fb_setcmap)(struct fb_cmap *cmap, struct fb_info *info);
+
 	/* blank display */
 	int (*fb_blank)(int blank, struct fb_info *info);

The old fb_setcolreg is a hang over from the old api. Every driver implemented the fb_setcolreg but not every one has a fb_setcmap. So I went with fb_setcolreg instead. I hope to see drivers move over to this function instead. The only question is how to avoid setting color register that don't need changes. That can be expensive.

-------------------------------------------------------
This SF.Net email is sponsored by: NEC IT Guy Games.
Get your fingers limbered up and give it your best shot. 4 great events, 4 opportunities to win big! Highest score wins.NEC IT Guy Games. Play to win an NEC 61 plasma display. Visit http://www.necitguy.com/?r=20