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usb: typec: tcpm: Don't block probing of consumers of "connector" nodes

PATCH In review Saravana Kannan 3 participants 3 messages May 6, 2021 – May 10, 2021

Subsystems (6)
USB ACPI Driver core USB Type-C class +2 more subsystems
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Saravana Kannan

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#0 lore raw

PATCH 1/1 usb: typec: tcpm: Don't block probing of consumers of "connector" nodes

fw_devlink expects DT device nodes with "compatible" property to have struct devices created for them. Since the connector node might not be populated as a device, mark it as such so that fw_devlink knows not to wait on this fwnode being populated as a struct device.

Without this patch, USB functionality can be broken on some boards.

Fixes f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
Reported-by John Stultz <[email protected]>
Signed-off-by Saravana Kannan <[email protected]>

---
Greg,

Probably better to take this in driver-core in case I need more fixes for fw_devlink on top of this. Those fixes are more likely to land in driver-core.

Hi John,

Can you please test this and give a Tested-by?

-Saravana

 drivers/base/core.c           | 3 ++-
 drivers/usb/typec/tcpm/tcpm.c | 9 +++++++++
 include/linux/fwnode.h        | 1 +
 3 files changed, 12 insertions(+), 1 deletion(-)
drivers/base/core.c +2 -1
index 4a8bf8cda52b..628e33939aca 100644
@@ -150,7 +150,7 @@ void fwnode_links_purge(struct fwnode_handle *fwnode)
 	fwnode_links_purge_consumers(fwnode);
 }
 
-static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
+void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
 {
 	struct fwnode_handle *child;
 

@@ -164,6 +164,7 @@ static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
 	fwnode_for_each_available_child_node(fwnode, child)
 		fw_devlink_purge_absent_suppliers(child);
 }
+EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers);
 
 #ifdef CONFIG_SRCU
 static DEFINE_MUTEX(device_links_lock);
drivers/usb/typec/tcpm/tcpm.c +9 -0
index c4fdc00a3bc8..bffa342d4e38 100644
@@ -5754,6 +5754,15 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
 	if (!fwnode)
 		return -EINVAL;
 
+	/*
+	 * This fwnode has a "compatible" property, but is never populated as a
+	 * struct device. Instead we simply parse it to read the properties.
+	 * This it breaks fw_devlink=on. To maintain backward compatibility
+	 * with existing DT files, we work around this by deleting any
+	 * fwnode_links to/from this fwnode.
+	 */
+	fw_devlink_purge_absent_suppliers(fwnode);
+
 	/* USB data support is optional */
 	ret = fwnode_property_read_string(fwnode, "data-role", &cap_str);
 	if (ret == 0) {
include/linux/fwnode.h +1 -0
index ed4e67a7ff1c..59828516ebaf 100644
@@ -187,5 +187,6 @@ extern u32 fw_devlink_get_flags(void);
 extern bool fw_devlink_is_strict(void);
 int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
 void fwnode_links_purge(struct fwnode_handle *fwnode);
+void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
 
 #endif
Signature · 1 line
2.31.1.527.g47e6f16901-goog
Tested-by on v1 1/1
#1 lore raw
Quoted 11 lines · Saravana Kannan

fw_devlink expects DT device nodes with "compatible" property to have struct devices created for them. Since the connector node might not be populated as a device, mark it as such so that fw_devlink knows not to wait on this fwnode being populated as a struct device.

Without this patch, USB functionality can be broken on some boards.

Fixes f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
Reported-by John Stultz <[email protected]>
Signed-off-by Saravana Kannan <[email protected]>
Tested-by John Stultz <[email protected]>

Thanks so much for this fix! HiKey960 is back to booting properly! -john

maintainer
#2 lore raw
Quoted 9 lines · John Stultz
Quoted 8 lines · Saravana Kannan

fw_devlink expects DT device nodes with "compatible" property to have struct devices created for them. Since the connector node might not be populated as a device, mark it as such so that fw_devlink knows not to wait on this fwnode being populated as a struct device.

Without this patch, USB functionality can be broken on some boards.

Quoted 8 lines
Quoted 3 lines
Fixes f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
Reported-by John Stultz <[email protected]>
Signed-off-by Saravana Kannan <[email protected]>
Tested-by John Stultz <[email protected]>

Thanks so much for this fix! HiKey960 is back to booting properly! -john

Now queued up, thanks.

greg k-h