-
Notifications
You must be signed in to change notification settings - Fork 0
/
vars.patch
84 lines (80 loc) · 2.69 KB
/
vars.patch
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 436d1776bc7b..4714c79babb1 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -431,6 +431,8 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
efi_char16_t *variable_name;
efi_status_t status;
efi_guid_t vendor_guid;
+ const int read_attempt_max = 16;
+ int read_attempt = 0;
int err = 0;
if (!__efivars)
@@ -449,17 +451,33 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
goto free;
}
- /*
- * Per EFI spec, the maximum storage allocated for both
- * the variable name and variable data is 1024 bytes.
- */
-
do {
- variable_name_size = 1024;
+ /*
+ * ASUS X470 boards with firmware 5007+ have a broken
+ * get_next_variable implementation, where the same
+ * variable is returned by multiple read calls. Work
+ * around the issue by giving the function a few more
+ * chances prior to erroring out.
+ */
+
+ read_attempt = 0;
+
+ do {
+ /*
+ * Per EFI spec, the maximum storage allocated for both
+ * the variable name and variable data is 1024 bytes.
+ */
+
+ variable_name_size = 1024;
+ read_attempt++;
+ status = ops->get_next_variable(&variable_name_size,
+ variable_name,
+ &vendor_guid);
+ } while (duplicates &&
+ read_attempt < read_attempt_max &&
+ status == EFI_SUCCESS &&
+ variable_is_present(variable_name, &vendor_guid, head));
- status = ops->get_next_variable(&variable_name_size,
- variable_name,
- &vendor_guid);
switch (status) {
case EFI_SUCCESS:
if (duplicates)
@@ -468,17 +486,18 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
variable_name_size = var_name_strnsize(variable_name,
variable_name_size);
+ if (read_attempt != 1) {
+ printk(KERN_WARNING "efivars: needed %d attempts "
+ "to advance to next the EFI variable\n",
+ read_attempt);
+ }
+
/*
- * Some firmware implementations return the
- * same variable name on multiple calls to
- * get_next_variable(). Terminate the loop
- * immediately as there is no guarantee that
- * we'll ever see a different variable name,
- * and may end up looping here forever.
+ * Terminate the loop immediately as there is no
+ * guarantee that we'll ever see a different variable
+ * name, and may end up looping here forever.
*/
- if (duplicates &&
- variable_is_present(variable_name, &vendor_guid,
- head)) {
+ if (duplicates && read_attempt == read_attempt_max) {
dup_variable_bug(variable_name, &vendor_guid,
variable_name_size);
status = EFI_NOT_FOUND;