Tunnels created by boot firmware results in incorrect PCI resource
allocation, which results in failure of extending daisy chain.
This series aligns with windows behaviour of performing a teardown of
tunnels and resetting the downstream ports using DPR during the init
sequence.
Sanath S (2):
thunderbolt: Introduce tb_switch_reset_ports(), tb_port_reset() and
usb4_port_reset()
thunderbolt: Teardown tunnels and reset downstream ports created by
boot firmware
drivers/thunderbolt/switch.c | 31 ++++++++
drivers/thunderbolt/tb.c | 137 ++--------------------------------
drivers/thunderbolt/tb.h | 2 +
drivers/thunderbolt/tb_regs.h | 1 +
drivers/thunderbolt/usb4.c | 39 ++++++++++
5 files changed, 80 insertions(+), 130 deletions(-)
--
2.34.1
Introduce the tb_switch_reset_ports() function that resets the
downstream ports of a given switch. This helps us reset the USB4
links created by boot firmware during the init sequence.
Introduce the tb_port_reset() helper function that resets the
given port.
Introduce the usb4_port_reset() function that performs the DPR
of a given port. This function follows the CM guide specification 7.3
Suggested-by: Mario Limonciello <[email protected]>
Signed-off-by: Sanath S <[email protected]>
---
drivers/thunderbolt/switch.c | 31 ++++++++++++++++++++++++++++
drivers/thunderbolt/tb.h | 2 ++
drivers/thunderbolt/tb_regs.h | 1 +
drivers/thunderbolt/usb4.c | 39 +++++++++++++++++++++++++++++++++++
4 files changed, 73 insertions(+)
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 44e9b09de47a..26ad6cc1ee91 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -626,6 +626,19 @@ int tb_port_unlock(struct tb_port *port)
return 0;
}
+/**
+ * tb_port_reset() - Reset downstream port
+ * @port: Port to reset
+ *
+ * Helps to reconfigure the USB4 link by resetting the downstream port.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_port_reset(struct tb_port *port)
+{
+ return usb4_port_reset(port);
+}
+
static int __tb_port_enable(struct tb_port *port, bool enable)
{
int ret;
@@ -1547,6 +1560,24 @@ static void tb_dump_switch(const struct tb *tb, const struct tb_switch *sw)
regs->__unknown1, regs->__unknown4);
}
+/**
+ * tb_switch_reset_ports() - Reset downstream ports of switch.
+ * @sw: Switch whose ports need to be reset.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_switch_reset_ports(struct tb_switch *sw)
+{
+ struct tb_port *port;
+ int ret = -EINVAL;
+
+ tb_switch_for_each_port(sw, port) {
+ if (tb_port_is_null(port) && port->cap_usb4)
+ ret = tb_port_reset(port);
+ }
+ return ret;
+}
+
/**
* tb_switch_reset() - reconfigure route, enable and send TB_CFG_PKG_RESET
* @sw: Switch to reset
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e299e53473ae..f2687ec4ac53 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -797,6 +797,7 @@ void tb_switch_remove(struct tb_switch *sw);
void tb_switch_suspend(struct tb_switch *sw, bool runtime);
int tb_switch_resume(struct tb_switch *sw);
int tb_switch_reset(struct tb_switch *sw);
+int tb_switch_reset_ports(struct tb_switch *sw);
int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
u32 value, int timeout_msec);
void tb_sw_set_unplugged(struct tb_switch *sw);
@@ -1281,6 +1282,7 @@ struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
int usb4_switch_add_ports(struct tb_switch *sw);
void usb4_switch_remove_ports(struct tb_switch *sw);
+int usb4_port_reset(struct tb_port *port);
int usb4_port_unlock(struct tb_port *port);
int usb4_port_hotplug_enable(struct tb_port *port);
int usb4_port_configure(struct tb_port *port);
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 87e4795275fe..d49530bc0d53 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -389,6 +389,7 @@ struct tb_regs_port_header {
#define PORT_CS_18_CSA BIT(22)
#define PORT_CS_18_TIP BIT(24)
#define PORT_CS_19 0x13
+#define PORT_CS_19_DPR BIT(0)
#define PORT_CS_19_PC BIT(3)
#define PORT_CS_19_PID BIT(4)
#define PORT_CS_19_WOC BIT(16)
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 4277733d0021..55f7c163bf84 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -1073,6 +1073,45 @@ void usb4_switch_remove_ports(struct tb_switch *sw)
}
}
+/**
+ * usb4_port_reset() - Reset USB4 downsteam port
+ * @port: USB4 port to reset.
+ *
+ * Helps to reconfigure USB4 link by resetting downstream port.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int usb4_port_reset(struct tb_port *port)
+{
+ int ret;
+ u32 val = 0;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_usb4 + PORT_CS_19, 1);
+ if (ret)
+ return ret;
+
+ val = val | PORT_CS_19_DPR;
+ ret = tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_usb4 + PORT_CS_19, 1);
+ if (ret)
+ return ret;
+
+ /* Wait for 10ms after requesting downstream port reset */
+ msleep(10);
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_usb4 + PORT_CS_19, 1);
+ if (ret)
+ return ret;
+
+ val &= ~PORT_CS_19_DPR;
+ ret = tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_usb4 + PORT_CS_19, 1);
+
+ return ret;
+}
+
/**
* usb4_port_unlock() - Unlock USB4 downstream port
* @port: USB4 port to unlock
--
2.34.1
Boot firmware might have created tunnels of its own. Since we cannot
be sure they are usable for us. Tear them down and reset the ports
to handle it as a new hotplug.
Since we teardown the tunnels, Discovering of tunnels is not needed.
Removing helper functions tb_discover_tunnels(),
tb_discover_dp_resources(), tb_create_usb3_tunnels(),
tb_add_dp_resources() and device_for_each_child().
Suggested-by: Mario Limonciello <[email protected]>
Signed-off-by: Sanath S <[email protected]>
---
drivers/thunderbolt/tb.c | 137 ++-------------------------------------
1 file changed, 7 insertions(+), 130 deletions(-)
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index fd49f86e0353..bfad14846514 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -151,24 +151,6 @@ tb_attach_bandwidth_group(struct tb_cm *tcm, struct tb_port *in,
return group;
}
-static void tb_discover_bandwidth_group(struct tb_cm *tcm, struct tb_port *in,
- struct tb_port *out)
-{
- if (usb4_dp_port_bandwidth_mode_enabled(in)) {
- int index, i;
-
- index = usb4_dp_port_group_id(in);
- for (i = 0; i < ARRAY_SIZE(tcm->groups); i++) {
- if (tcm->groups[i].index == index) {
- tb_bandwidth_group_attach_port(&tcm->groups[i], in);
- return;
- }
- }
- }
-
- tb_attach_bandwidth_group(tcm, in, out);
-}
-
static void tb_detach_bandwidth_group(struct tb_port *in)
{
struct tb_bandwidth_group *group = in->group;
@@ -247,32 +229,6 @@ static void tb_remove_dp_resources(struct tb_switch *sw)
}
}
-static void tb_discover_dp_resource(struct tb *tb, struct tb_port *port)
-{
- struct tb_cm *tcm = tb_priv(tb);
- struct tb_port *p;
-
- list_for_each_entry(p, &tcm->dp_resources, list) {
- if (p == port)
- return;
- }
-
- tb_port_dbg(port, "DP %s resource available discovered\n",
- tb_port_is_dpin(port) ? "IN" : "OUT");
- list_add_tail(&port->list, &tcm->dp_resources);
-}
-
-static void tb_discover_dp_resources(struct tb *tb)
-{
- struct tb_cm *tcm = tb_priv(tb);
- struct tb_tunnel *tunnel;
-
- list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
- if (tb_tunnel_is_dp(tunnel))
- tb_discover_dp_resource(tb, tunnel->dst_port);
- }
-}
-
/* Enables CL states up to host router */
static int tb_enable_clx(struct tb_switch *sw)
{
@@ -472,34 +428,6 @@ static void tb_switch_discover_tunnels(struct tb_switch *sw,
}
}
-static void tb_discover_tunnels(struct tb *tb)
-{
- struct tb_cm *tcm = tb_priv(tb);
- struct tb_tunnel *tunnel;
-
- tb_switch_discover_tunnels(tb->root_switch, &tcm->tunnel_list, true);
-
- list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
- if (tb_tunnel_is_pci(tunnel)) {
- struct tb_switch *parent = tunnel->dst_port->sw;
-
- while (parent != tunnel->src_port->sw) {
- parent->boot = true;
- parent = tb_switch_parent(parent);
- }
- } else if (tb_tunnel_is_dp(tunnel)) {
- struct tb_port *in = tunnel->src_port;
- struct tb_port *out = tunnel->dst_port;
-
- /* Keep the domain from powering down */
- pm_runtime_get_sync(&in->sw->dev);
- pm_runtime_get_sync(&out->sw->dev);
-
- tb_discover_bandwidth_group(tcm, in, out);
- }
- }
-}
-
static int tb_port_configure_xdomain(struct tb_port *port, struct tb_xdomain *xd)
{
if (tb_switch_is_usb4(port->sw))
@@ -1043,31 +971,6 @@ static int tb_tunnel_usb3(struct tb *tb, struct tb_switch *sw)
return ret;
}
-static int tb_create_usb3_tunnels(struct tb_switch *sw)
-{
- struct tb_port *port;
- int ret;
-
- if (!tb_acpi_may_tunnel_usb3())
- return 0;
-
- if (tb_route(sw)) {
- ret = tb_tunnel_usb3(sw->tb, sw);
- if (ret)
- return ret;
- }
-
- tb_switch_for_each_port(sw, port) {
- if (!tb_port_has_remote(port))
- continue;
- ret = tb_create_usb3_tunnels(port->remote->sw);
- if (ret)
- return ret;
- }
-
- return 0;
-}
-
/**
* tb_configure_asym() - Transition links to asymmetric if needed
* @tb: Domain structure
@@ -2534,27 +2437,6 @@ static void tb_stop(struct tb *tb)
tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
}
-static int tb_scan_finalize_switch(struct device *dev, void *data)
-{
- if (tb_is_switch(dev)) {
- struct tb_switch *sw = tb_to_switch(dev);
-
- /*
- * If we found that the switch was already setup by the
- * boot firmware, mark it as authorized now before we
- * send uevent to userspace.
- */
- if (sw->boot)
- sw->authorized = 1;
-
- dev_set_uevent_suppress(dev, false);
- kobject_uevent(&dev->kobj, KOBJ_ADD);
- device_for_each_child(dev, NULL, tb_scan_finalize_switch);
- }
-
- return 0;
-}
-
static int tb_start(struct tb *tb)
{
struct tb_cm *tcm = tb_priv(tb);
@@ -2598,20 +2480,15 @@ static int tb_start(struct tb *tb)
tb_switch_tmu_enable(tb->root_switch);
/* 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 */
- tb_discover_tunnels(tb);
- /* Add DP resources from the DP tunnels created by the boot firmware */
- tb_discover_dp_resources(tb);
/*
- * If the boot firmware did not create USB 3.x tunnels create them
- * now for the whole topology.
+ * Boot firmware might have created tunnels of its own. Since we cannot
+ * be sure they are usable for us, Tear them down and reset the ports
+ * to handle it as new hotplug.
*/
- tb_create_usb3_tunnels(tb->root_switch);
- /* Add DP IN resources for the root switch */
- tb_add_dp_resources(tb->root_switch);
- /* Make the discovered switches available to the userspace */
- device_for_each_child(&tb->root_switch->dev, NULL,
- tb_scan_finalize_switch);
+ tb_switch_discover_tunnels(tb->root_switch, &tcm->tunnel_list, false);
+ ret = tb_switch_reset_ports(tb->root_switch);
+ if (ret)
+ return ret;
/* Allow tb_handle_hotplug to progress events */
tcm->hotplug_active = true;
--
2.34.1
On Tue, Dec 12, 2023 at 07:30:47PM +0530, Sanath S wrote:
> Boot firmware might have created tunnels of its own. Since we cannot
> be sure they are usable for us. Tear them down and reset the ports
> to handle it as a new hotplug.
>
> Since we teardown the tunnels, Discovering of tunnels is not needed.
Let's leave this for non-USB4 (That's TBT1-3) as we agreed.
On Tue, Dec 12, 2023 at 07:30:46PM +0530, Sanath S wrote:
> Introduce the tb_switch_reset_ports() function that resets the
> downstream ports of a given switch. This helps us reset the USB4
> links created by boot firmware during the init sequence.
>
> Introduce the tb_port_reset() helper function that resets the
> given port.
>
> Introduce the usb4_port_reset() function that performs the DPR
> of a given port. This function follows the CM guide specification 7.3
>
> Suggested-by: Mario Limonciello <[email protected]>
> Signed-off-by: Sanath S <[email protected]>
> ---
> drivers/thunderbolt/switch.c | 31 ++++++++++++++++++++++++++++
> drivers/thunderbolt/tb.h | 2 ++
> drivers/thunderbolt/tb_regs.h | 1 +
> drivers/thunderbolt/usb4.c | 39 +++++++++++++++++++++++++++++++++++
> 4 files changed, 73 insertions(+)
>
> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
> index 44e9b09de47a..26ad6cc1ee91 100644
> --- a/drivers/thunderbolt/switch.c
> +++ b/drivers/thunderbolt/switch.c
> @@ -626,6 +626,19 @@ int tb_port_unlock(struct tb_port *port)
> return 0;
> }
>
> +/**
> + * tb_port_reset() - Reset downstream port
> + * @port: Port to reset
> + *
> + * Helps to reconfigure the USB4 link by resetting the downstream port.
> + *
> + * Return: Returns 0 on success or an error code on failure.
> + */
> +static int tb_port_reset(struct tb_port *port)
> +{
> + return usb4_port_reset(port);
> +}
> +
> static int __tb_port_enable(struct tb_port *port, bool enable)
> {
> int ret;
> @@ -1547,6 +1560,24 @@ static void tb_dump_switch(const struct tb *tb, const struct tb_switch *sw)
> regs->__unknown1, regs->__unknown4);
> }
>
> +/**
> + * tb_switch_reset_ports() - Reset downstream ports of switch.
> + * @sw: Switch whose ports need to be reset.
> + *
> + * Return: Returns 0 on success or an error code on failure.
> + */
> +int tb_switch_reset_ports(struct tb_switch *sw)
> +{
> + struct tb_port *port;
> + int ret = -EINVAL;
Why it returns -EINVAL? What if this is run for non-USB4 router?
> +
> + tb_switch_for_each_port(sw, port) {
> + if (tb_port_is_null(port) && port->cap_usb4)
> + ret = tb_port_reset(port);
Should it stop here and return ret?
> + }
> + return ret;
> +}
> +
> /**
> * tb_switch_reset() - reconfigure route, enable and send TB_CFG_PKG_RESET
> * @sw: Switch to reset
> diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
> index e299e53473ae..f2687ec4ac53 100644
> --- a/drivers/thunderbolt/tb.h
> +++ b/drivers/thunderbolt/tb.h
> @@ -797,6 +797,7 @@ void tb_switch_remove(struct tb_switch *sw);
> void tb_switch_suspend(struct tb_switch *sw, bool runtime);
> int tb_switch_resume(struct tb_switch *sw);
> int tb_switch_reset(struct tb_switch *sw);
> +int tb_switch_reset_ports(struct tb_switch *sw);
> int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
> u32 value, int timeout_msec);
> void tb_sw_set_unplugged(struct tb_switch *sw);
> @@ -1281,6 +1282,7 @@ struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
> int usb4_switch_add_ports(struct tb_switch *sw);
> void usb4_switch_remove_ports(struct tb_switch *sw);
>
> +int usb4_port_reset(struct tb_port *port);
> int usb4_port_unlock(struct tb_port *port);
> int usb4_port_hotplug_enable(struct tb_port *port);
> int usb4_port_configure(struct tb_port *port);
> diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
> index 87e4795275fe..d49530bc0d53 100644
> --- a/drivers/thunderbolt/tb_regs.h
> +++ b/drivers/thunderbolt/tb_regs.h
> @@ -389,6 +389,7 @@ struct tb_regs_port_header {
> #define PORT_CS_18_CSA BIT(22)
> #define PORT_CS_18_TIP BIT(24)
> #define PORT_CS_19 0x13
> +#define PORT_CS_19_DPR BIT(0)
> #define PORT_CS_19_PC BIT(3)
> #define PORT_CS_19_PID BIT(4)
> #define PORT_CS_19_WOC BIT(16)
> diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
> index 4277733d0021..55f7c163bf84 100644
> --- a/drivers/thunderbolt/usb4.c
> +++ b/drivers/thunderbolt/usb4.c
> @@ -1073,6 +1073,45 @@ void usb4_switch_remove_ports(struct tb_switch *sw)
> }
> }
>
> +/**
> + * usb4_port_reset() - Reset USB4 downsteam port
> + * @port: USB4 port to reset.
> + *
> + * Helps to reconfigure USB4 link by resetting downstream port.
> + *
> + * Return: Returns 0 on success or an error code on failure.
> + */
> +int usb4_port_reset(struct tb_port *port)
> +{
> + int ret;
> + u32 val = 0;
Reverse christmas tree please:
u32 val = 0;
int ret;
> +
> + ret = tb_port_read(port, &val, TB_CFG_PORT,
> + port->cap_usb4 + PORT_CS_19, 1);
> + if (ret)
> + return ret;
> +
> + val = val | PORT_CS_19_DPR;
> + ret = tb_port_write(port, &val, TB_CFG_PORT,
> + port->cap_usb4 + PORT_CS_19, 1);
> + if (ret)
> + return ret;
> +
> + /* Wait for 10ms after requesting downstream port reset */
> + msleep(10);
Probably good to add a couple of more ms just in case. Also
usleep_range()? (or fsleep()).
> +
> + ret = tb_port_read(port, &val, TB_CFG_PORT,
> + port->cap_usb4 + PORT_CS_19, 1);
> + if (ret)
> + return ret;
> +
> + val &= ~PORT_CS_19_DPR;
> + ret = tb_port_write(port, &val, TB_CFG_PORT,
> + port->cap_usb4 + PORT_CS_19, 1);
> +
> + return ret;
> +}
> +
> /**
> * usb4_port_unlock() - Unlock USB4 downstream port
> * @port: USB4 port to unlock
> --
> 2.34.1
On 12/12/2023 09:27, Mika Westerberg wrote:
> On Tue, Dec 12, 2023 at 07:30:46PM +0530, Sanath S wrote:
>> Introduce the tb_switch_reset_ports() function that resets the
>> downstream ports of a given switch. This helps us reset the USB4
>> links created by boot firmware during the init sequence.
>>
>> Introduce the tb_port_reset() helper function that resets the
>> given port.
>>
>> Introduce the usb4_port_reset() function that performs the DPR
>> of a given port. This function follows the CM guide specification 7.3
>>
>> Suggested-by: Mario Limonciello <[email protected]>
>> Signed-off-by: Sanath S <[email protected]>
>> ---
>> drivers/thunderbolt/switch.c | 31 ++++++++++++++++++++++++++++
>> drivers/thunderbolt/tb.h | 2 ++
>> drivers/thunderbolt/tb_regs.h | 1 +
>> drivers/thunderbolt/usb4.c | 39 +++++++++++++++++++++++++++++++++++
>> 4 files changed, 73 insertions(+)
>>
>> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
>> index 44e9b09de47a..26ad6cc1ee91 100644
>> --- a/drivers/thunderbolt/switch.c
>> +++ b/drivers/thunderbolt/switch.c
>> @@ -626,6 +626,19 @@ int tb_port_unlock(struct tb_port *port)
>> return 0;
>> }
>>
>> +/**
>> + * tb_port_reset() - Reset downstream port
>> + * @port: Port to reset
>> + *
>> + * Helps to reconfigure the USB4 link by resetting the downstream port.
>> + *
>> + * Return: Returns 0 on success or an error code on failure.
>> + */
>> +static int tb_port_reset(struct tb_port *port)
>> +{
>> + return usb4_port_reset(port);
>> +}
>> +
>> static int __tb_port_enable(struct tb_port *port, bool enable)
>> {
>> int ret;
>> @@ -1547,6 +1560,24 @@ static void tb_dump_switch(const struct tb *tb, const struct tb_switch *sw)
>> regs->__unknown1, regs->__unknown4);
>> }
>>
>> +/**
>> + * tb_switch_reset_ports() - Reset downstream ports of switch.
>> + * @sw: Switch whose ports need to be reset.
>> + *
>> + * Return: Returns 0 on success or an error code on failure.
>> + */
>> +int tb_switch_reset_ports(struct tb_switch *sw)
>> +{
>> + struct tb_port *port;
>> + int ret = -EINVAL;
>
> Why it returns -EINVAL? What if this is run for non-USB4 router?
This is a good point, but in the non USB4 case (default return) maybe
it's better to be -ENODEV and in patch 2 be careful about the caller.
>
>> +
>> + tb_switch_for_each_port(sw, port) {
>> + if (tb_port_is_null(port) && port->cap_usb4)
>> + ret = tb_port_reset(port);
>
> Should it stop here and return ret?
+1
>
>> + }
>> + return ret;
>> +}
>> +
>> /**
>> * tb_switch_reset() - reconfigure route, enable and send TB_CFG_PKG_RESET
>> * @sw: Switch to reset
>> diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
>> index e299e53473ae..f2687ec4ac53 100644
>> --- a/drivers/thunderbolt/tb.h
>> +++ b/drivers/thunderbolt/tb.h
>> @@ -797,6 +797,7 @@ void tb_switch_remove(struct tb_switch *sw);
>> void tb_switch_suspend(struct tb_switch *sw, bool runtime);
>> int tb_switch_resume(struct tb_switch *sw);
>> int tb_switch_reset(struct tb_switch *sw);
>> +int tb_switch_reset_ports(struct tb_switch *sw);
>> int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
>> u32 value, int timeout_msec);
>> void tb_sw_set_unplugged(struct tb_switch *sw);
>> @@ -1281,6 +1282,7 @@ struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
>> int usb4_switch_add_ports(struct tb_switch *sw);
>> void usb4_switch_remove_ports(struct tb_switch *sw);
>>
>> +int usb4_port_reset(struct tb_port *port);
>> int usb4_port_unlock(struct tb_port *port);
>> int usb4_port_hotplug_enable(struct tb_port *port);
>> int usb4_port_configure(struct tb_port *port);
>> diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
>> index 87e4795275fe..d49530bc0d53 100644
>> --- a/drivers/thunderbolt/tb_regs.h
>> +++ b/drivers/thunderbolt/tb_regs.h
>> @@ -389,6 +389,7 @@ struct tb_regs_port_header {
>> #define PORT_CS_18_CSA BIT(22)
>> #define PORT_CS_18_TIP BIT(24)
>> #define PORT_CS_19 0x13
>> +#define PORT_CS_19_DPR BIT(0)
>> #define PORT_CS_19_PC BIT(3)
>> #define PORT_CS_19_PID BIT(4)
>> #define PORT_CS_19_WOC BIT(16)
>> diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
>> index 4277733d0021..55f7c163bf84 100644
>> --- a/drivers/thunderbolt/usb4.c
>> +++ b/drivers/thunderbolt/usb4.c
>> @@ -1073,6 +1073,45 @@ void usb4_switch_remove_ports(struct tb_switch *sw)
>> }
>> }
>>
>> +/**
>> + * usb4_port_reset() - Reset USB4 downsteam port
>> + * @port: USB4 port to reset.
>> + *
>> + * Helps to reconfigure USB4 link by resetting downstream port.
>> + *
>> + * Return: Returns 0 on success or an error code on failure.
>> + */
>> +int usb4_port_reset(struct tb_port *port)
>> +{
>> + int ret;
>> + u32 val = 0;
>
> Reverse christmas tree please:
>
> u32 val = 0;
> int ret;
>
>> +
>> + ret = tb_port_read(port, &val, TB_CFG_PORT,
>> + port->cap_usb4 + PORT_CS_19, 1);
>> + if (ret)
>> + return ret;
>> +
>> + val = val | PORT_CS_19_DPR;
>> + ret = tb_port_write(port, &val, TB_CFG_PORT,
>> + port->cap_usb4 + PORT_CS_19, 1);
>> + if (ret)
>> + return ret;
>> +
>> + /* Wait for 10ms after requesting downstream port reset */
>> + msleep(10);
>
> Probably good to add a couple of more ms just in case. Also
> usleep_range()? (or fsleep()).
Sanath had it at 20 but I had suggested to align to spec.
For the wiggle room maybe usleep_range(10000, 15000)?
>
>> +
>> + ret = tb_port_read(port, &val, TB_CFG_PORT,
>> + port->cap_usb4 + PORT_CS_19, 1);
>> + if (ret)
>> + return ret;
>> +
>> + val &= ~PORT_CS_19_DPR;
>> + ret = tb_port_write(port, &val, TB_CFG_PORT,
>> + port->cap_usb4 + PORT_CS_19, 1);
>> +
>> + return ret;
>> +}
>> +
>> /**
>> * usb4_port_unlock() - Unlock USB4 downstream port
>> * @port: USB4 port to unlock
>> --
>> 2.34.1
On Tue, Dec 12, 2023 at 09:32:03AM -0600, Mario Limonciello wrote:
> On 12/12/2023 09:27, Mika Westerberg wrote:
> > On Tue, Dec 12, 2023 at 07:30:46PM +0530, Sanath S wrote:
> > > Introduce the tb_switch_reset_ports() function that resets the
> > > downstream ports of a given switch. This helps us reset the USB4
> > > links created by boot firmware during the init sequence.
> > >
> > > Introduce the tb_port_reset() helper function that resets the
> > > given port.
> > >
> > > Introduce the usb4_port_reset() function that performs the DPR
> > > of a given port. This function follows the CM guide specification 7.3
> > >
> > > Suggested-by: Mario Limonciello <[email protected]>
> > > Signed-off-by: Sanath S <[email protected]>
> > > ---
> > > drivers/thunderbolt/switch.c | 31 ++++++++++++++++++++++++++++
> > > drivers/thunderbolt/tb.h | 2 ++
> > > drivers/thunderbolt/tb_regs.h | 1 +
> > > drivers/thunderbolt/usb4.c | 39 +++++++++++++++++++++++++++++++++++
> > > 4 files changed, 73 insertions(+)
> > >
> > > diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
> > > index 44e9b09de47a..26ad6cc1ee91 100644
> > > --- a/drivers/thunderbolt/switch.c
> > > +++ b/drivers/thunderbolt/switch.c
> > > @@ -626,6 +626,19 @@ int tb_port_unlock(struct tb_port *port)
> > > return 0;
> > > }
> > > +/**
> > > + * tb_port_reset() - Reset downstream port
> > > + * @port: Port to reset
> > > + *
> > > + * Helps to reconfigure the USB4 link by resetting the downstream port.
> > > + *
> > > + * Return: Returns 0 on success or an error code on failure.
> > > + */
> > > +static int tb_port_reset(struct tb_port *port)
> > > +{
> > > + return usb4_port_reset(port);
> > > +}
> > > +
> > > static int __tb_port_enable(struct tb_port *port, bool enable)
> > > {
> > > int ret;
> > > @@ -1547,6 +1560,24 @@ static void tb_dump_switch(const struct tb *tb, const struct tb_switch *sw)
> > > regs->__unknown1, regs->__unknown4);
> > > }
> > > +/**
> > > + * tb_switch_reset_ports() - Reset downstream ports of switch.
> > > + * @sw: Switch whose ports need to be reset.
> > > + *
> > > + * Return: Returns 0 on success or an error code on failure.
> > > + */
> > > +int tb_switch_reset_ports(struct tb_switch *sw)
> > > +{
> > > + struct tb_port *port;
> > > + int ret = -EINVAL;
> >
> > Why it returns -EINVAL? What if this is run for non-USB4 router?
>
> This is a good point, but in the non USB4 case (default return) maybe it's
> better to be -ENODEV and in patch 2 be careful about the caller.
Or -EOPNOTSUPP (to be consistent with the rest of the driver). Add this
to the kernel-doc too so that the caller needs to make sure
tb_switch_is_usb4() is called before this one or so.
>
> >
> > > +
> > > + tb_switch_for_each_port(sw, port) {
> > > + if (tb_port_is_null(port) && port->cap_usb4)
> > > + ret = tb_port_reset(port);
> >
> > Should it stop here and return ret?
>
> +1
>
> >
> > > + }
> > > + return ret;
> > > +}
> > > +
> > > /**
> > > * tb_switch_reset() - reconfigure route, enable and send TB_CFG_PKG_RESET
> > > * @sw: Switch to reset
> > > diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
> > > index e299e53473ae..f2687ec4ac53 100644
> > > --- a/drivers/thunderbolt/tb.h
> > > +++ b/drivers/thunderbolt/tb.h
> > > @@ -797,6 +797,7 @@ void tb_switch_remove(struct tb_switch *sw);
> > > void tb_switch_suspend(struct tb_switch *sw, bool runtime);
> > > int tb_switch_resume(struct tb_switch *sw);
> > > int tb_switch_reset(struct tb_switch *sw);
> > > +int tb_switch_reset_ports(struct tb_switch *sw);
> > > int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
> > > u32 value, int timeout_msec);
> > > void tb_sw_set_unplugged(struct tb_switch *sw);
> > > @@ -1281,6 +1282,7 @@ struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
> > > int usb4_switch_add_ports(struct tb_switch *sw);
> > > void usb4_switch_remove_ports(struct tb_switch *sw);
> > > +int usb4_port_reset(struct tb_port *port);
> > > int usb4_port_unlock(struct tb_port *port);
> > > int usb4_port_hotplug_enable(struct tb_port *port);
> > > int usb4_port_configure(struct tb_port *port);
> > > diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
> > > index 87e4795275fe..d49530bc0d53 100644
> > > --- a/drivers/thunderbolt/tb_regs.h
> > > +++ b/drivers/thunderbolt/tb_regs.h
> > > @@ -389,6 +389,7 @@ struct tb_regs_port_header {
> > > #define PORT_CS_18_CSA BIT(22)
> > > #define PORT_CS_18_TIP BIT(24)
> > > #define PORT_CS_19 0x13
> > > +#define PORT_CS_19_DPR BIT(0)
> > > #define PORT_CS_19_PC BIT(3)
> > > #define PORT_CS_19_PID BIT(4)
> > > #define PORT_CS_19_WOC BIT(16)
> > > diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
> > > index 4277733d0021..55f7c163bf84 100644
> > > --- a/drivers/thunderbolt/usb4.c
> > > +++ b/drivers/thunderbolt/usb4.c
> > > @@ -1073,6 +1073,45 @@ void usb4_switch_remove_ports(struct tb_switch *sw)
> > > }
> > > }
> > > +/**
> > > + * usb4_port_reset() - Reset USB4 downsteam port
> > > + * @port: USB4 port to reset.
> > > + *
> > > + * Helps to reconfigure USB4 link by resetting downstream port.
> > > + *
> > > + * Return: Returns 0 on success or an error code on failure.
> > > + */
> > > +int usb4_port_reset(struct tb_port *port)
> > > +{
> > > + int ret;
> > > + u32 val = 0;
> >
> > Reverse christmas tree please:
> >
> > u32 val = 0;
> > int ret;
> >
> > > +
> > > + ret = tb_port_read(port, &val, TB_CFG_PORT,
> > > + port->cap_usb4 + PORT_CS_19, 1);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + val = val | PORT_CS_19_DPR;
> > > + ret = tb_port_write(port, &val, TB_CFG_PORT,
> > > + port->cap_usb4 + PORT_CS_19, 1);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + /* Wait for 10ms after requesting downstream port reset */
> > > + msleep(10);
> >
> > Probably good to add a couple of more ms just in case. Also
> > usleep_range()? (or fsleep()).
>
> Sanath had it at 20 but I had suggested to align to spec.
> For the wiggle room maybe usleep_range(10000, 15000)?
Works for me.
>
> >
> > > +
> > > + ret = tb_port_read(port, &val, TB_CFG_PORT,
> > > + port->cap_usb4 + PORT_CS_19, 1);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + val &= ~PORT_CS_19_DPR;
> > > + ret = tb_port_write(port, &val, TB_CFG_PORT,
> > > + port->cap_usb4 + PORT_CS_19, 1);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > /**
> > > * usb4_port_unlock() - Unlock USB4 downstream port
> > > * @port: USB4 port to unlock
> > > --
> > > 2.34.1