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authorMika Westerberg <mika.westerberg@linux.intel.com>2017-06-06 14:24:54 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-09 11:42:41 +0200
commit08a5e4cebec543bfa4a6d119fc18f0ed8fd9d8ce (patch)
tree09adf22c1a45da2763ebbf933dbe4f0079106bd9 /drivers/thunderbolt
parentthunderbolt: Use const buffer pointer in write operations (diff)
downloadlinux-08a5e4cebec543bfa4a6d119fc18f0ed8fd9d8ce.tar.xz
linux-08a5e4cebec543bfa4a6d119fc18f0ed8fd9d8ce.zip
thunderbolt: No need to read UID of the root switch on resume
The root switch is part of the host controller and cannot be physically removed, so there is no point of reading UID again on resume in order to check if the root switch is still the same. Suggested-by: Andreas Noever <andreas.noever@gmail.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Andreas Noever <andreas.noever@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/thunderbolt')
-rw-r--r--drivers/thunderbolt/switch.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index c6f30b1695a9..81f5164a6364 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -452,19 +452,26 @@ void tb_sw_set_unplugged(struct tb_switch *sw)
int tb_switch_resume(struct tb_switch *sw)
{
int i, err;
- u64 uid;
tb_sw_info(sw, "resuming switch\n");
- err = tb_drom_read_uid_only(sw, &uid);
- if (err) {
- tb_sw_warn(sw, "uid read failed\n");
- return err;
- }
- if (sw != sw->tb->root_switch && sw->uid != uid) {
- tb_sw_info(sw,
- "changed while suspended (uid %#llx -> %#llx)\n",
- sw->uid, uid);
- return -ENODEV;
+ /*
+ * Check for UID of the connected switches except for root
+ * switch which we assume cannot be removed.
+ */
+ if (tb_route(sw)) {
+ u64 uid;
+
+ err = tb_drom_read_uid_only(sw, &uid);
+ if (err) {
+ tb_sw_warn(sw, "uid read failed\n");
+ return err;
+ }
+ if (sw->uid != uid) {
+ tb_sw_info(sw,
+ "changed while suspended (uid %#llx -> %#llx)\n",
+ sw->uid, uid);
+ return -ENODEV;
+ }
}
/* upload configuration */