[PATCH v2] firmware: change kernel read fail to dev_dbg()

["Luis R. Rodriguez" <mcgrof@kernel.org>]

When we now use the new kernel_read_file_from_path() we
are reporting a failure when we iterate over all the paths
possible for firmware. Before using kernel_read_file_from_path()
we only reported a failure once we confirmed a file existed
with filp_open() but failed with fw_read_file_contents().

With kernel_read_file_from_path() both are done for us and
we obviously are now reporting too much information given that
some optional paths will always fail and clutter the logs.

fw_get_filesystem_firmware() already has a check for failure
and uses an internal flag, FW_OPT_NO_WARN, but this does not
let us capture other unxpected errors. This enables that
as changed by Neil via commit:

"firmware: Be a bit more verbose about direct firmware loading failure"

Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_class.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 1cff832ab74e..9503a88b189b 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -328,8 +328,12 @@ static int fw_get_filesystem_firmware(struct device *device,
 		rc = kernel_read_file_from_path(path, &buf->data, &size,
 						INT_MAX, READING_FIRMWARE);
 		if (rc) {
-			dev_warn(device, "loading %s failed with error %d\n",
-				 path, rc);
+			if (rc == -ENOENT)
+				dev_dbg(device, "loading %s failed with error %d\n",
+					 path, rc);
+			else
+				dev_warn(device, "loading %s failed with error %d\n",
+					 path, rc);
 			continue;
 		}
 		dev_dbg(device, "direct-loading %s\n", buf->fw_id);
-- 
2.7.0