nvidiafb: bring back generic ddc reading

Make nvidiafb use fb_ddc_read().  This patch was submitted before but was
reverted due to problems in a non-x86 platform.  This includes a fix for that
where ddc reading is bypassed if there is no DDC bus (duh).
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/nvidia/nv_i2c.c

@@ -70,8 +70,6 @@ static int nvidia_gpio_getscl(void *data)
 	if (VGA_RD08(par->PCIO, 0x3d5) & 0x04)
 		val = 1;
 
-	val = VGA_RD08(par->PCIO, 0x3d5);
-
 	return val;
 }
 
@@ -159,51 +157,13 @@ void nvidia_delete_i2c_busses(struct nvidia_par *par)
 
 }
 
-static u8 *nvidia_do_probe_i2c_edid(struct nvidia_i2c_chan *chan)
-{
-	u8 start = 0x0;
-	struct i2c_msg msgs[] = {
-		{
-		 .addr = 0x50,
-		 .len = 1,
-		 .buf = &start,
-		 }, {
-		     .addr = 0x50,
-		     .flags = I2C_M_RD,
-		     .len = EDID_LENGTH,
-		     },
-	};
-	u8 *buf;
-
-	if (!chan->par)
-		return NULL;
-
-	buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
-	if (!buf) {
-		dev_warn(&chan->par->pci_dev->dev, "Out of memory!\n");
-		return NULL;
-	}
-	msgs[1].buf = buf;
-
-	if (i2c_transfer(&chan->adapter, msgs, 2) == 2)
-		return buf;
-	dev_dbg(&chan->par->pci_dev->dev, "Unable to read EDID block.\n");
-	kfree(buf);
-	return NULL;
-}
-
 int nvidia_probe_i2c_connector(struct fb_info *info, int conn, u8 **out_edid)
 {
 	struct nvidia_par *par = info->par;
 	u8 *edid = NULL;
-	int i;
 
-	for (i = 0; i < 3; i++) {
-		/* Do the real work */
-		edid = nvidia_do_probe_i2c_edid(&par->chan[conn - 1]);
-		if (edid)
-			break;
-	}
+	if (par->chan[conn - 1].par)
+		edid = fb_ddc_read(&par->chan[conn - 1].adapter);
 
 	if (!edid && conn == 1) {
 		/* try to get from firmware */