--- zzzz-none-000/linux-3.10.107/drivers/char/agp/frontend.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/char/agp/frontend.c	2021-02-04 17:41:59.000000000 +0000
@@ -31,7 +31,6 @@
 #include <linux/module.h>
 #include <linux/mman.h>
 #include <linux/pci.h>
-#include <linux/init.h>
 #include <linux/miscdevice.h>
 #include <linux/agp_backend.h>
 #include <linux/agpgart.h>
@@ -603,7 +602,8 @@
 			vma->vm_ops = kerninfo.vm_ops;
 		} else if (io_remap_pfn_range(vma, vma->vm_start,
 				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
-					    size, vma->vm_page_prot)) {
+				size,
+				pgprot_writecombine(vma->vm_page_prot))) {
 			goto out_again;
 		}
 		mutex_unlock(&(agp_fe.agp_mutex));
@@ -618,8 +618,9 @@
 		if (kerninfo.vm_ops) {
 			vma->vm_ops = kerninfo.vm_ops;
 		} else if (io_remap_pfn_range(vma, vma->vm_start,
-					    kerninfo.aper_base >> PAGE_SHIFT,
-					    size, vma->vm_page_prot)) {
+				kerninfo.aper_base >> PAGE_SHIFT,
+				size,
+				pgprot_writecombine(vma->vm_page_prot))) {
 			goto out_again;
 		}
 		mutex_unlock(&(agp_fe.agp_mutex));
@@ -709,19 +710,6 @@
 	return 0;
 }
 
-
-static ssize_t agp_read(struct file *file, char __user *buf,
-			size_t count, loff_t * ppos)
-{
-	return -EINVAL;
-}
-
-static ssize_t agp_write(struct file *file, const char __user *buf,
-			 size_t count, loff_t * ppos)
-{
-	return -EINVAL;
-}
-
 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
 {
 	struct agp_info userinfo;
@@ -729,6 +717,7 @@
 
 	agp_copy_info(agp_bridge, &kerninfo);
 
+	memset(&userinfo, 0, sizeof(userinfo));
 	userinfo.version.major = kerninfo.version.major;
 	userinfo.version.minor = kerninfo.version.minor;
 	userinfo.bridge_id = kerninfo.device->vendor |
@@ -1045,8 +1034,6 @@
 {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
-	.read		= agp_read,
-	.write		= agp_write,
 	.unlocked_ioctl	= agp_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= compat_agp_ioctl,