From: Mika Westerberg mika.westerberg@linux.intel.com
[ Upstream commit 9d2d0a5cf0ca063f417681cc33e767ce52615286 ]
Brad reported that on Apple hardware with Light Ridge or Falcon Ridge controller, plugging in a chain of Thunderbolt displays (Light Ridge based controllers) causes all kinds of tearing and flickering. The reason for this is that on Thunderbolt 1 hardware there is no lane bonding so we have two independent 10 Gb/s lanes, and currently Linux tunnels both displays through the lane 1. This makes the displays to share the 10 Gb/s bandwidth which may not be enough for higher resolutions.
For this reason make the second tunnel go through the lane 0 instead. This seems to match what the macOS connection manager is also doing.
Reported-by: Brad Campbell lists2009@fnarfbargle.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Tested-by: Brad Campbell lists2009@fnarfbargle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/thunderbolt/tb.c | 19 +++++++++++++++++-- drivers/thunderbolt/test.c | 16 ++++++++-------- drivers/thunderbolt/tunnel.c | 11 ++++++----- drivers/thunderbolt/tunnel.h | 4 ++-- 4 files changed, 33 insertions(+), 17 deletions(-)
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c index 9beb47b31c75..44d04b651a8b 100644 --- a/drivers/thunderbolt/tb.c +++ b/drivers/thunderbolt/tb.c @@ -867,7 +867,7 @@ static struct tb_port *tb_find_dp_out(struct tb *tb, struct tb_port *in)
static void tb_tunnel_dp(struct tb *tb) { - int available_up, available_down, ret; + int available_up, available_down, ret, link_nr; struct tb_cm *tcm = tb_priv(tb); struct tb_port *port, *in, *out; struct tb_tunnel *tunnel; @@ -912,6 +912,20 @@ static void tb_tunnel_dp(struct tb *tb) return; }
+ /* + * This is only applicable to links that are not bonded (so + * when Thunderbolt 1 hardware is involved somewhere in the + * topology). For these try to share the DP bandwidth between + * the two lanes. + */ + link_nr = 1; + list_for_each_entry(tunnel, &tcm->tunnel_list, list) { + if (tb_tunnel_is_dp(tunnel)) { + link_nr = 0; + break; + } + } + /* * DP stream needs the domain to be active so runtime resume * both ends of the tunnel. @@ -943,7 +957,8 @@ static void tb_tunnel_dp(struct tb *tb) tb_dbg(tb, "available bandwidth for new DP tunnel %u/%u Mb/s\n", available_up, available_down);
- tunnel = tb_tunnel_alloc_dp(tb, in, out, available_up, available_down); + tunnel = tb_tunnel_alloc_dp(tb, in, out, link_nr, available_up, + available_down); if (!tunnel) { tb_port_dbg(out, "could not allocate DP tunnel\n"); goto err_reclaim; diff --git a/drivers/thunderbolt/test.c b/drivers/thunderbolt/test.c index 1f69bab236ee..66b6e665e96f 100644 --- a/drivers/thunderbolt/test.c +++ b/drivers/thunderbolt/test.c @@ -1348,7 +1348,7 @@ static void tb_test_tunnel_dp(struct kunit *test) in = &host->ports[5]; out = &dev->ports[13];
- tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, tunnel != NULL); KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP); KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in); @@ -1394,7 +1394,7 @@ static void tb_test_tunnel_dp_chain(struct kunit *test) in = &host->ports[5]; out = &dev4->ports[14];
- tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, tunnel != NULL); KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP); KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in); @@ -1444,7 +1444,7 @@ static void tb_test_tunnel_dp_tree(struct kunit *test) in = &dev2->ports[13]; out = &dev5->ports[13];
- tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, tunnel != NULL); KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP); KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in); @@ -1509,7 +1509,7 @@ static void tb_test_tunnel_dp_max_length(struct kunit *test) in = &dev6->ports[13]; out = &dev12->ports[13];
- tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, tunnel != NULL); KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP); KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in); @@ -1627,7 +1627,7 @@ static void tb_test_tunnel_port_on_path(struct kunit *test) in = &dev2->ports[13]; out = &dev5->ports[13];
- dp_tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + dp_tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, dp_tunnel != NULL);
KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, in)); @@ -2009,7 +2009,7 @@ static void tb_test_credit_alloc_dp(struct kunit *test) in = &host->ports[5]; out = &dev->ports[14];
- tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, tunnel != NULL); KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)3);
@@ -2245,7 +2245,7 @@ static struct tb_tunnel *TB_TEST_DP_TUNNEL1(struct kunit *test,
in = &host->ports[5]; out = &dev->ports[13]; - dp_tunnel1 = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + dp_tunnel1 = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, dp_tunnel1 != NULL); KUNIT_ASSERT_EQ(test, dp_tunnel1->npaths, (size_t)3);
@@ -2282,7 +2282,7 @@ static struct tb_tunnel *TB_TEST_DP_TUNNEL2(struct kunit *test,
in = &host->ports[6]; out = &dev->ports[14]; - dp_tunnel2 = tb_tunnel_alloc_dp(NULL, in, out, 0, 0); + dp_tunnel2 = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0); KUNIT_ASSERT_TRUE(test, dp_tunnel2 != NULL); KUNIT_ASSERT_EQ(test, dp_tunnel2->npaths, (size_t)3);
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c index 118742ec93ed..8ccd70920b6a 100644 --- a/drivers/thunderbolt/tunnel.c +++ b/drivers/thunderbolt/tunnel.c @@ -858,6 +858,7 @@ struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in, * @tb: Pointer to the domain structure * @in: DP in adapter port * @out: DP out adapter port + * @link_nr: Preferred lane adapter when the link is not bonded * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0 * if not limited) * @max_down: Maximum available downstream bandwidth for the DP tunnel @@ -869,8 +870,8 @@ struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in, * Return: Returns a tb_tunnel on success or NULL on failure. */ struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in, - struct tb_port *out, int max_up, - int max_down) + struct tb_port *out, int link_nr, + int max_up, int max_down) { struct tb_tunnel *tunnel; struct tb_path **paths; @@ -894,21 +895,21 @@ struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in, paths = tunnel->paths;
path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID, - 1, "Video"); + link_nr, "Video"); if (!path) goto err_free; tb_dp_init_video_path(path); paths[TB_DP_VIDEO_PATH_OUT] = path;
path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out, - TB_DP_AUX_TX_HOPID, 1, "AUX TX"); + TB_DP_AUX_TX_HOPID, link_nr, "AUX TX"); if (!path) goto err_free; tb_dp_init_aux_path(path); paths[TB_DP_AUX_PATH_OUT] = path;
path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in, - TB_DP_AUX_RX_HOPID, 1, "AUX RX"); + TB_DP_AUX_RX_HOPID, link_nr, "AUX RX"); if (!path) goto err_free; tb_dp_init_aux_path(path); diff --git a/drivers/thunderbolt/tunnel.h b/drivers/thunderbolt/tunnel.h index 03e56076b5bc..bb4d1f1d6d0b 100644 --- a/drivers/thunderbolt/tunnel.h +++ b/drivers/thunderbolt/tunnel.h @@ -71,8 +71,8 @@ struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up, struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in, bool alloc_hopid); struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in, - struct tb_port *out, int max_up, - int max_down); + struct tb_port *out, int link_nr, + int max_up, int max_down); struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi, struct tb_port *dst, int transmit_path, int transmit_ring, int receive_path,