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authorMika Westerberg <mika.westerberg@linux.intel.com>2019-12-17 15:33:40 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-12-18 17:38:55 +0300
commitb04079837b2094f09e145676eec4b9a56ae8a6aa (patch)
tree53c6fc96150e61db8225c2210eb2e28dd8a2672f /drivers/thunderbolt/xdomain.c
parent210e9f56e9e12472741b949950f9efcebf350750 (diff)
downloadlinux-b04079837b2094f09e145676eec4b9a56ae8a6aa.tar.xz
thunderbolt: Add initial support for USB4
USB4 is the public specification based on Thunderbolt 3 protocol. There are some differences in register layouts and flows. In addition to PCIe and DP tunneling, USB4 supports tunneling of USB 3.x. USB4 is also backward compatible with Thunderbolt 3 (and older generations but the spec only talks about 3rd generation). USB4 compliant devices can be identified by checking USB4 version field in router configuration space. This patch adds initial support for USB4 compliant hosts and devices which enables following features provided by the existing functionality in the driver: - PCIe tunneling - Display Port tunneling - Host and device NVM firmware upgrade - P2P networking This brings the USB4 support to the same level that we already have for Thunderbolt 1, 2 and 3 devices. Note the spec talks about host and device "routers" but in the driver we still use term "switch" in most places. Both can be used interchangeably. Co-developed-by: Rajmohan Mani <rajmohan.mani@intel.com> Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Link: https://lore.kernel.org/r/20191217123345.31850-5-mika.westerberg@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/thunderbolt/xdomain.c')
-rw-r--r--drivers/thunderbolt/xdomain.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index 880d784398a3..053f918e00e8 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -1220,7 +1220,13 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
u64 route, const uuid_t *local_uuid,
const uuid_t *remote_uuid)
{
+ struct tb_switch *parent_sw = tb_to_switch(parent);
struct tb_xdomain *xd;
+ struct tb_port *down;
+
+ /* Make sure the downstream domain is accessible */
+ down = tb_port_at(route, parent_sw);
+ tb_port_unlock(down);
xd = kzalloc(sizeof(*xd), GFP_KERNEL);
if (!xd)