Re: [PATCH BlueZ 01/15] doc/qualification: gap-pics: add footnote for TSPC_GAP_21_9 feature

Hi Luiz,

On Friday, 27 February 2026, 17:32:55 CET, Luiz Augusto von Dentz wrote:

Hi Christian,

On Fri, Feb 27, 2026 at 11:08 AM Christian Eggers [off-list ref] wrote:

quoted

This feature is not supported by some host controllers (e.g. RTL8761BU)
and must be disabled with such hardware.
---
 doc/qualification/gap-pics.rst | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/doc/qualification/gap-pics.rst b/doc/qualification/gap-pics.rst
index f5b63a00ac98..d7673e5da088 100644
--- a/doc/qualification/gap-pics.rst
+++ b/doc/qualification/gap-pics.rst

@@ -832,7 +832,7 @@ Prerequisite: GAP 5/3 "Peripheral (LE)" OR GAP 38/3 "Peripheral (BR/EDR/LE)"
 | TSPC_GAP_21_8    | x        | Peripheral-initiated Feature Exchange        |
 |                  |          | procedure (C.1)                              |
 +------------------+----------+----------------------------------------------+
-| TSPC_GAP_21_9    | x        | Connection Parameter Request procedure (O)   |
+| TSPC_GAP_21_9    | x(1)     | Connection Parameter Request procedure (O)   |
 +------------------+----------+----------------------------------------------+
 | TSPC_GAP_21_10   |          | Data Length Update procedure (O)             |
 +------------------+----------+----------------------------------------------+

@@ -848,6 +848,15 @@ Prerequisite: GAP 5/3 "Peripheral (LE)" OR GAP 38/3 "Peripheral (BR/EDR/LE)"
   otherwise Optional.
 - C.2: Excluded IF SUM ICS 31/17 "Core v4.2" OR SUM ICS 31/18 "Core v4.2+HS",
   otherwise Optional.
+- (1) Only set of Bluetooth controller supports the HCI_LE_CONN_PARAM_REQ_PROC

Ok, I could also write "Connection Parameters Request procedure" here

quoted

+  LE feature, otherwise, GAP/CONN/CPUP/BV-08-C will fail.
+  # cat /sys/kernel/debug/bluetooth/hci0/features
+   0: ff ff ff fe db fd 7b 87
+   1: 02 00 00 00 00 00 00 00
+   2: 5f 02 00 00 00 00 00 00
+  LE: bd 5f 66 00 00 00 00 00
+      ^^
+      ++- This byte must have the 2nd bit (0x02) set.

I think we might want to say exactly what feature it is rather than
just the hexdump and point to the expected value, perhaps this
requires Connection Parameters Request procedure?
https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Core-62/out/en/low-energy-controller/link-layer-specification.html#UUID-56ada5ed-4ae3-acee-198f-27ead57d86f1

Yes, this is the feature which is required.

Requiring debugfs for this is also not optimal. Is there any (not already
obsoleted) command line tool where querying of the LE features could be added?

regards,
Christian

quoted

 LE Capability Statement
 =======================
--
2.51.0