Commit a9fdf5f9 authored by Mika Westerberg's avatar Mika Westerberg
Browse files

thunderbolt: Check that lane 1 is in CL0 before enabling lane bonding 



Marek reported that when BlackMagic UltraStudio device is connected the
kernel repeatedly tries to enable lane bonding without success making
the device non-functional. It looks like the device does not have lane 1
connected at all so even though it is enabled we should not try to bond
the lanes. For this reason check that lane 1 is in fact CL0 (connected,
active) before attempting to bond the lanes.

Reported-by: default avatarMarek Šanta <teslan223@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217737


Cc: stable@vger.kernel.org
Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent 582620d9

drivers/thunderbolt/switch.c

+7 −0
Original line number Diff line number Diff line
@@ -2725,6 +2725,13 @@ int tb_switch_lane_bonding_enable(struct tb_switch *sw) 
	    !tb_port_is_width_supported(down, TB_LINK_WIDTH_DUAL))

		return 0;



	/*

	 * Both lanes need to be in CL0. Here we assume lane 0 already be in

	 * CL0 and check just for lane 1.

	 */

	if (tb_wait_for_port(down->dual_link_port, false) <= 0)

		return -ENOTCONN;



	ret = tb_port_lane_bonding_enable(up);

	if (ret) {

		tb_port_warn(up, "failed to enable lane bonding\n");