From 11cd1d6a7b04574be475926cf29b18a127e89a04 Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Tue, 6 Jun 2017 15:24:55 +0300
Subject: [PATCH 03/34] thunderbolt: Do not try to read UID if DROM offset is
read as 0
Git-commit: df1421b5f72979e48096f68c253f59aa7e8e7468
Patch-mainline: v4.13-rc1
References: FATE#323948
At least Falcon Ridge when in host mode does not have any kind of DROM
available and reading DROM offset returns 0 for these. Do not try to
read DROM any further in that case.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/thunderbolt/eeprom.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 6392990c984d..e4e64b130514 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -276,6 +276,9 @@ int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid)
if (res)
return res;
+ if (drom_offset == 0)
+ return -ENODEV;
+
/* read uid */
res = tb_eeprom_read_n(sw, drom_offset, data, 9);
if (res)
--
2.12.3