diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index b28d2f1253bbc927731afa08022fdef21a598a24..1ba67dc8006ab700170afb6964954c33c5705591 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -634,6 +634,18 @@ static int __init ppro_init(char **cpu_type)
 	if (force_arch_perfmon && cpu_has_arch_perfmon)
 		return 0;
 
+	/*
+	 * Documentation on identifying Intel processors by CPU family
+	 * and model can be found in the Intel Software Developer's
+	 * Manuals (SDM):
+	 *
+	 *  http://www.intel.com/products/processor/manuals/
+	 *
+	 * As of May 2010 the documentation for this was in the:
+	 * "Intel 64 and IA-32 Architectures Software Developer's
+	 * Manual Volume 3B: System Programming Guide", "Table B-1
+	 * CPUID Signature Values of DisplayFamily_DisplayModel".
+	 */
 	switch (cpu_model) {
 	case 0 ... 2:
 		*cpu_type = "i386/ppro";
@@ -655,12 +667,12 @@ static int __init ppro_init(char **cpu_type)
 	case 15: case 23:
 		*cpu_type = "i386/core_2";
 		break;
+	case 0x1a:
 	case 0x2e:
-	case 26:
 		spec = &op_arch_perfmon_spec;
 		*cpu_type = "i386/core_i7";
 		break;
-	case 28:
+	case 0x1c:
 		*cpu_type = "i386/atom";
 		break;
 	default:
diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c
index 5df60a6b67766adb402a30fee44d7b7782bc5e08..dd87e86048be7913e9cc0090c52a957712d0067c 100644
--- a/drivers/oprofile/event_buffer.c
+++ b/drivers/oprofile/event_buffer.c
@@ -135,7 +135,7 @@ static int event_buffer_open(struct inode *inode, struct file *file)
 	 * echo 1 >/dev/oprofile/enable
 	 */
 
-	return 0;
+	return nonseekable_open(inode, file);
 
 fail:
 	dcookie_unregister(file->private_data);
@@ -205,4 +205,5 @@ const struct file_operations event_buffer_fops = {
 	.open		= event_buffer_open,
 	.release	= event_buffer_release,
 	.read		= event_buffer_read,
+	.llseek		= no_llseek,
 };