bluetooth: host: Add extended feature set support #92856

sean-madigan · 2025-07-08T16:12:15Z

bluetooth: host: Add support for extended feature set feature

This commit adds support for the extended feature set
feature. This includes:

hci boilerplate
kconfigs, including one for a variable sized feature array
linking into the current auto feature exchange procedure

subsys/bluetooth/host/conn.c

Thalley

Some minor formatting comments, otherwise LGTM

include/zephyr/bluetooth/conn.h

subsys/bluetooth/host/conn.c

subsys/bluetooth/host/hci_core.c

include/zephyr/bluetooth/bluetooth.h

subsys/bluetooth/host/shell/bt.c

lylezhu2012 · 2025-07-11T02:53:57Z

subsys/bluetooth/host/hci_core.c

+
+	/* Read Low Energy Supported Features */
+	if (IS_ENABLED(CONFIG_BT_LE_EXTENDED_FEAT_SET)) {
+		err = bt_hci_cmd_send_sync(BT_HCI_OP_LE_READ_ALL_LOCAL_SUPPORTED_FEATURES, NULL,


It seems that this does not take into account that the controller may not support the command HCI_LE_Read_All_Local_Supported_Features.

If CONFIG_BT_LE_EXTENDED_FEAT_SET is set, and controller does not support command HCI_LE_Read_All_Local_Supported_Features, the Host cannot be initialized properly.

My suggestion is,

Read controller supported commands,

Send command HCI_LE_Read_All_Local_Supported_Features or HCI_LE_Read_Local_Supported_Features_Page_0 depending on the response.

I think this is a good point. If CONFIG_BT_LE_EXTENDED_FEAT_SET=y in the host only, then I think we will actually fail reading any locally supported features.

I think Lyle makes a good argument to read the controller supported commands first

Yeah good point, will check the controller supported commands

include/zephyr/bluetooth/conn.h

Thalley · 2025-07-11T07:50:36Z

subsys/bluetooth/host/hci_core.c

+
+	/* Read Low Energy Supported Features */
+	if (IS_ENABLED(CONFIG_BT_LE_EXTENDED_FEAT_SET)) {
+		err = bt_hci_cmd_send_sync(BT_HCI_OP_LE_READ_ALL_LOCAL_SUPPORTED_FEATURES, NULL,


I think this is a good point. If CONFIG_BT_LE_EXTENDED_FEAT_SET=y in the host only, then I think we will actually fail reading any locally supported features.

I think Lyle makes a good argument to read the controller supported commands first

Thalley · 2025-07-11T07:52:46Z

subsys/bluetooth/host/shell/bt.c

+		bt_shell_fprintf_print(
+			"Read all remote features complete, Max Remote Page %d, LE Features: 0x",
+			params->max_remote_page);
+
+		for (uint8_t i = number_of_bytes; i > 0; i--) {
+			uint8_t features = params->features[i];
+			char features_str[(2 * sizeof(uint8_t)) + 1];
+
+			bin2hex(&features, sizeof(features), features_str, sizeof(features_str));
+			bt_shell_fprintf_print("%s", features_str);
+		}
+		bt_shell_fprintf_print("\n");


How does this look in the terminal? (Just curious)

I guess it'd be too demanding to convert these values to string / human readable values? :D

Looks like this currently

uart:~$ bt read-all-remote-features 10 Read all remote features complete, Max Remote Page 1, LE Features: 0x0000000000000000000000000000000000000000000000010080000127f70049

Copilot

Pull Request Overview

This PR adds support for Bluetooth 6.0's Extended Feature Set feature to the Zephyr Bluetooth host stack. This allows the host to read extended feature pages from both local and remote devices beyond the standard page 0 features.

Implements HCI commands for reading all local and remote supported features with extended pages
Adds Kconfig options for enabling the feature and configuring maximum feature pages
Integrates extended feature exchange into existing connection procedures and shell commands

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/bluetooth/shell/testcase.yaml	Adds test configuration for extended feature set
subsys/bluetooth/host/shell/bt.c	Implements shell command and callback for reading all remote features
subsys/bluetooth/host/hci_core.c	Adds HCI event handling and command logic for extended features
subsys/bluetooth/host/conn_internal.h	Declares notification function for extended feature complete event
subsys/bluetooth/host/conn.c	Implements connection API for reading all remote features and notification logic
subsys/bluetooth/controller/Kconfig	Adds controller-side Kconfig for extended feature set support
subsys/bluetooth/common/Kconfig	Updates HCI event buffer size for extended feature set
subsys/bluetooth/Kconfig	Adds host-side Kconfig options for extended feature set
include/zephyr/bluetooth/hci_types.h	Defines HCI structures and constants for extended feature commands/events
include/zephyr/bluetooth/conn.h	Adds connection callback and API for extended feature set
include/zephyr/bluetooth/bluetooth.h	Updates local features structure to support variable-sized feature arrays

Comments suppressed due to low confidence (1)

subsys/bluetooth/host/shell/bt.c:1343

The error message references 'bt_hci_le_read_all_remote_features' but the actual function called is 'bt_conn_le_read_all_remote_features'. The error message should match the function name.

	.biginfo = per_adv_sync_biginfo_cb,

subsys/bluetooth/host/shell/bt.c

subsys/bluetooth/host/hci_core.c

include/zephyr/bluetooth/hci_types.h

alwa-nordic · 2025-07-15T09:06:00Z

include/zephyr/bluetooth/bluetooth.h

 	 * See Bluetooth Core Specification, Vol 6, Part B, Section 4.6.
 	 */
-	uint8_t features[BT_LE_LOCAL_SUPPORTED_FEATURES_SIZE];
+	const uint8_t *features;


I think this is a breaking API change. Please keep it as an array for now, and if there a significant optimization to be done here, we can open a separate PR to discuss this.

Otherwise, we need to add a point to the migration guide and document a lifetime for this pointer.

I was wondering the same.

From a user perspective, if it's a pointer or an array, doesn't really matter that much does it?
The addition of const may be considered breaking if the array was modified by users.

It's a shame we didn't manage to get this PR merged for 4.2, as this was added in 4.2 as well

I'll take this in a separate pr

From a user perspective, if it's a pointer or an array, doesn't really matter that much does it? The addition of const may be considered breaking if the array was modified by users.

const is indeed breaking, but I don't expect users would write to this anyway.

sizeof the field is no longer tied to BT_LE_LOCAL_SUPPORTED_FEATURES_SIZE. This one is a bit more insidious since it change the meaning of programs without causing compile errors. But maybe this is not such a big deal since you would use atomic_get_bit on this usually. ¹.

What is the lifetime?, i.e. at what point can this value change or become invalid? It's probably valid until bt_disable, right? Then that has to be documented. And even if it's not a problem in practice (though how sure are you about this?), it's clearly more awkward and complex than a simple pass-by-value copy.

Footnotes

This is a good example of why it would be good to specify the accepted interface for interacting with an object. If it was stated that this field can only be accessed as atomic_get_bit((bt_le_local_features rvalue).features, 0), then both const and sizeof changes would be non-breaking. ↩

include/zephyr/bluetooth/conn.h

Addressed

include/zephyr/bluetooth/conn.h

This commit adds support for the extended feature set feature. This includes: - hci boilerplate - kconfigs, including one for a max local feature page - reading remote features is done by a command and callback - this is not linked into the auto feature request on connection as this procedure can take quite a few connection events, and we do not want to delay the user - added the commands to the bt shell Signed-off-by: Sean Madigan <sean.madigan@nordicsemi.no>

sonarqubecloud · 2025-07-16T15:20:13Z

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

sean-madigan force-pushed the add_extended_feature_set_support branch from aec05a5 to 85d2316 Compare July 9, 2025 07:47

sean-madigan changed the title ~~Add extended feature set support~~ bluetooth: host: Add extended feature set support Jul 9, 2025

sean-madigan force-pushed the add_extended_feature_set_support branch 5 times, most recently from f498fee to c51a877 Compare July 9, 2025 11:38

sean-madigan marked this pull request as ready for review July 9, 2025 12:18

github-actions bot added area: Bluetooth Classic Bluetooth Classic (BR/EDR) area: Bluetooth Controller area: Bluetooth Host Bluetooth Host (excluding BR/EDR) area: Bluetooth labels Jul 9, 2025

github-actions bot requested review from alwa-nordic, carlescufi, cvinayak, erbr-ot, gzh-terry, hermabe, jhedberg, lylezhu2012, MarkWangChinese, rugeGerritsen, sjanc, Thalley, thoh-ot, Tronil and wopu-ot July 9, 2025 12:19

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bluetooth: host: Add extended feature set support #92856

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Pull Request Overview

Reviewed Changes

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Footnotes

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sonarqubecloud bot commented Jul 16, 2025

Quality Gate passed

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sean-madigan commented Jul 8, 2025 •

edited

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