* [PATCH BlueZ v1] monitor: Decode Intel DDC LE extended features
@ 2026-07-30 17:51 Luiz Augusto von Dentz
2026-07-30 19:45 ` [BlueZ,v1] " bluez.test.bot
0 siblings, 1 reply; 2+ messages in thread
From: Luiz Augusto von Dentz @ 2026-07-30 17:51 UTC (permalink / raw)
To: linux-bluetooth
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The Intel DDC Config Write command (0x3f|0x008b) can carry identifier
0x031f which holds the 248 octet LE extended features array, using the
same layout as LE Read All Local Features: page 0 is 8 octets followed
by 10 pages of 24 octets each.
Decode it with the existing LE feature tables instead of dumping raw
hex, and make the parameter loop stop on truncated/padded entries.
Example, setting only the SCI bits on page 1 (bits 8 and 9):
hcitool cmd 0x3F 0x008B 0xFA 0x1F 0x03 \
0xFF 0xF9 0x01 0x3F 0xBE 0x00 0x00 0x80 \
0x00 0x03 0x00 0x00 ... (padding up to 248 octets)
< HCI Command: Intel DDC Config Write (0x3f|0x008b) plen 251
Identifier: 0x031f
Features[0/0][8]:
ff f9 01 3f be 00 00 80 ...?....
LE Encryption
Connection Parameter Request Procedure
...
LL Extended Feature Set
Features[1/0][8]:
00 03 00 00 00 00 00 00 ........
Shorter Connection Intervals
Shorter Connection Intervals (Host Support)
Features[1/1][8]:
00 00 00 00 00 00 00 00 ........
...
---
monitor/intel.c | 33 +++++++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/monitor/intel.c b/monitor/intel.c
index cd997d24b59c..782fda675422 100644
--- a/monitor/intel.c
+++ b/monitor/intel.c
@@ -681,14 +681,43 @@ static void set_event_mask_cmd(uint16_t index, const void *data, uint8_t size)
"(0x%16.16" PRIx64 ")", mask);
}
+#define DDC_ID_LE_EXT_FEATURES 0x031f
+
+/* LE extended features: page 0 is 8 octets, pages 1-10 are 24 octets each */
+static void print_ddc_le_ext_features(const uint8_t *features, uint8_t len)
+{
+ uint8_t i;
+
+ if (len < 8) {
+ packet_hexdump(features, len);
+ return;
+ }
+
+ packet_print_features_ext_ll(0, features);
+
+ for (i = 0; i < 10 && len >= 8 + (i + 1) * 24; i++)
+ packet_print_features_ext_ll(i + 1, features + 8 + i * 24);
+}
+
static void ddc_config_write_cmd(uint16_t index, const void *data, uint8_t size)
{
- while (size > 0) {
+ while (size > 2) {
uint8_t param_len = get_u8(data);
uint16_t param_id = get_le16(data + 1);
+ if (param_len < 2 || param_len + 1 > size)
+ break;
+
print_field("Identifier: 0x%4.4x", param_id);
- packet_hexdump(data + 3, param_len - 2);
+
+ switch (param_id) {
+ case DDC_ID_LE_EXT_FEATURES:
+ print_ddc_le_ext_features(data + 3, param_len - 2);
+ break;
+ default:
+ packet_hexdump(data + 3, param_len - 2);
+ break;
+ }
data += param_len + 1;
size -= param_len + 1;
--
2.54.0
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2026-07-30 17:51 [PATCH BlueZ v1] monitor: Decode Intel DDC LE extended features Luiz Augusto von Dentz
2026-07-30 19:45 ` [BlueZ,v1] " bluez.test.bot
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