diff mbox series

[v4,4/6] thunderbolt: Change downstream router's TMU rate in both TMU uni/bidir mode

Message ID 20220526105921.17214-5-gil.fine@intel.com
State New
Headers show
Series thunderbolt: CL1 support for USB4 and Titan Ridge | expand

Commit Message

Gil Fine May 26, 2022, 10:59 a.m. UTC 
In case of uni-directional time sync, TMU handshake is
initiated by upstream router. In case of bi-directional
time sync, TMU handshake is initiated by downstream router.
In order to handle correctly the case of uni-directional mode,
we avoid changing the upstream router's rate to off,
because it might have another downstream router plugged that is set to
uni-directional mode (and we don't want to change its mode).
Instead, we always change downstream router's rate.

Signed-off-by: Gil Fine <gil.fine@intel.com>
---
 drivers/thunderbolt/tmu.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/thunderbolt/tmu.c b/drivers/thunderbolt/tmu.c
index b656659d02fb..985ca43b8f39 100644
--- a/drivers/thunderbolt/tmu.c
+++ b/drivers/thunderbolt/tmu.c
@@ -359,13 +359,14 @@  int tb_switch_tmu_disable(struct tb_switch *sw)
 		 * In case of uni-directional time sync, TMU handshake is
 		 * initiated by upstream router. In case of bi-directional
 		 * time sync, TMU handshake is initiated by downstream router.
-		 * Therefore, we change the rate to off in the respective
-		 * router.
+		 * We change downstream router's rate to off for both uni/bidir
+		 * cases although it is needed only for the bi-directional mode.
+		 * We avoid changing upstream router's mode since it might
+		 * have another downstream router plugged, that is set to
+		 * uni-directional mode and we don't want to change it's TMU
+		 * mode.
 		 */
-		if (unidirectional)
-			tb_switch_tmu_rate_write(parent, TB_SWITCH_TMU_RATE_OFF);
-		else
-			tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_OFF);
+		tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_OFF);
 
 		tb_port_tmu_time_sync_disable(up);
 		ret = tb_port_tmu_time_sync_disable(down);