[PATCH] firmware: dmi: handle missing DMI data gracefully

From: Ard Biesheuvel
Date: Thu Oct 12 2017 - 16:03:39 EST


Currently, when booting a kernel with DMI support on a platform that has
no DMI tables, the following output is emitted into the kernel log:

[ 0.128818] DMI not present or invalid.
...
[ 1.306659] dmi: Firmware registration failed.
...
[ 2.908681] dmi-sysfs: dmi entry is absent.

The first one is a pr_info(), but the subsequent ones are pr_err()s that
complain about a condition that is not really an error to begin with.

So let's clean this up, and give up silently if dma_available is not set.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
drivers/firmware/dmi-sysfs.c | 3 +++
drivers/firmware/dmi_scan.c | 6 ++----
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
index d5de6ee8466d..3a264cbbb5a6 100644
--- a/drivers/firmware/dmi-sysfs.c
+++ b/drivers/firmware/dmi-sysfs.c
@@ -651,6 +651,9 @@ static int __init dmi_sysfs_init(void)
int error;
int val;

+ if (!dmi_available)
+ return 0;
+
if (!dmi_kobj) {
pr_err("dmi-sysfs: dmi entry is absent.\n");
error = -ENODATA;
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 783041964439..17a7425063c2 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -715,10 +715,8 @@ static int __init dmi_init(void)
u8 *dmi_table;
int ret = -ENOMEM;

- if (!dmi_available) {
- ret = -ENODATA;
- goto err;
- }
+ if (!dmi_available)
+ return 0;

/*
* Set up dmi directory at /sys/firmware/dmi. This entry should stay
--
2.11.0