Messages in this thread Patch in this message | | | Date | Tue, 9 Aug 2022 18:50:28 +0300 | From | Mika Westerberg <> | Subject | Re: Apple Thunderbolt Display chaining |
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Hi,
On Tue, Aug 09, 2022 at 11:16:27PM +0800, Brad Campbell wrote: > If I then reboot and load the driver it fails. > > The only thing I could think of doing was an lspci -vvv after the boot and module load > and an lspci -vvv after a warm reboot and diff them, because there are changes around the > thunderbolt bridge devices. I've done a diff -u50 to try and keep as much context as possible. > > On the first boot I can unload/reload the thunderbolt module repeatedly and there's no issue > but loading it after a reboot locks up. There are no lspci changes on the first boot after the > initial module load unless I rescan the PCI bus, but they're minor and it doesn't cause an issue > with loading the thunderbolt module. > > The firmware *must* be doing something on reboot I suppose or the PCIe configs wouldn't change.
Okay, let's try a bigger hammer and reset all the ports upon load. That should hopefully clear out the "bad state" too. This is completely untested but it should trigger reset and then re-initialize the TBT links.
diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c index 633970fbe9b0..c419c2568de4 100644 --- a/drivers/thunderbolt/lc.c +++ b/drivers/thunderbolt/lc.c @@ -6,6 +6,8 @@ * Author: Mika Westerberg <mika.westerberg@linux.intel.com> */ +#include <linux/delay.h> + #include "tb.h" /** @@ -327,6 +329,34 @@ void tb_lc_xhci_disconnect(struct tb_port *port) tb_port_dbg(port, "xHCI disconnected\n"); } +int tb_lc_reset_port(struct tb_port *port) +{ + struct tb_switch *sw = port->sw; + int cap, ret; + u32 val; + + if (sw->generation != 3) + return -EINVAL; + + cap = find_port_lc_cap(port); + if (cap < 0) + return cap; + + ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); + if (ret) + return ret; + + val |= TB_LC_PORT_MODE_DPR; + ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); + if (ret) + return ret; + + msleep(20); + + val &= ~TB_LC_PORT_MODE_DPR; + return tb_sw_write(sw, &val, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); +} + static int tb_lc_set_wake_one(struct tb_switch *sw, unsigned int offset, unsigned int flags) { diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 0ae8a7ec7c9c..21ac3ccf1cf9 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -740,6 +740,11 @@ int tb_port_disable(struct tb_port *port) return __tb_port_enable(port, false); } +int tb_port_reset(struct tb_port *port) +{ + return tb_lc_reset_port(port); +} + /* * tb_init_port() - initialize a port * diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c index 8030fc544c5e..48a7396994ef 100644 --- a/drivers/thunderbolt/tb.c +++ b/drivers/thunderbolt/tb.c @@ -1875,6 +1875,7 @@ static int tb_scan_finalize_switch(struct device *dev, void *data) static int tb_start(struct tb *tb) { struct tb_cm *tcm = tb_priv(tb); + struct tb_port *p; int ret; tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0); @@ -1911,6 +1912,12 @@ static int tb_start(struct tb *tb) false); /* Enable TMU if it is off */ tb_switch_tmu_enable(tb->root_switch); + + tb_switch_for_each_port(tb->root_switch, p) { + if (tb_port_is_null(p)) + tb_port_reset(p); + } + /* Full scan to discover devices added before the driver was loaded. */ tb_scan_switch(tb->root_switch); /* Find out tunnels created by the boot firmware */ diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h index 28bb80d967d6..fe5edefec712 100644 --- a/drivers/thunderbolt/tb.h +++ b/drivers/thunderbolt/tb.h @@ -1028,6 +1028,7 @@ int tb_port_clear_counter(struct tb_port *port, int counter); int tb_port_unlock(struct tb_port *port); int tb_port_enable(struct tb_port *port); int tb_port_disable(struct tb_port *port); +int tb_port_reset(struct tb_port *port); int tb_port_alloc_in_hopid(struct tb_port *port, int hopid, int max_hopid); void tb_port_release_in_hopid(struct tb_port *port, int hopid); int tb_port_alloc_out_hopid(struct tb_port *port, int hopid, int max_hopid); @@ -1121,6 +1122,7 @@ bool tb_lc_is_usb_plugged(struct tb_port *port); bool tb_lc_is_xhci_connected(struct tb_port *port); int tb_lc_xhci_connect(struct tb_port *port); void tb_lc_xhci_disconnect(struct tb_port *port); +int tb_lc_reset_port(struct tb_port *port); int tb_lc_set_wake(struct tb_switch *sw, unsigned int flags); int tb_lc_set_sleep(struct tb_switch *sw); bool tb_lc_lane_bonding_possible(struct tb_switch *sw); diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h index f8c1ca3464d9..8fd12bc2d500 100644 --- a/drivers/thunderbolt/tb_regs.h +++ b/drivers/thunderbolt/tb_regs.h @@ -555,6 +555,9 @@ struct tb_regs_hop { #define TB_LC_POWER 0x740 /* Link controller registers */ +#define TB_LC_PORT_MODE 0x26 +#define TB_LC_PORT_MODE_DPR BIT(6) + #define TB_LC_CS_42 0x2a #define TB_LC_CS_42_USB_PLUGGED BIT(31)
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