[RFC PATCH] Bluetooth: l2cap: honor local LE connection interval range

[RFC PATCH] Bluetooth: l2cap: honor local LE connection interval range

[Kyle Pepper]

Intersect a valid peer request with the locally configured interval
range. Reject disjoint ranges and preserve validation of the original
request before applying local policy.

Assisted-by: OpenCode:gpt-6.1-sol
Signed-off-by: Kyle Pepper <cochcoder@proton.me>
---
Submission review notes (not part of the commit message):
October 12 no-intersection trial accepts [16,24] and completes 30 ms
with STATUS 03 02 18 and normal host TX; the user hears silence. Volume
and multi-day acoustic comparison controls are incomplete. The working
intersection yields 20 ms. Maximum-only rejection failed in kernel 5
and is not this proposal. Generic minimum/range policy and LL-path
consistency remain RFC questions, not established by one renderer.

 net/bluetooth/l2cap_core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 49a998804..49e201d3e 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4968,6 +4968,13 @@ static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
 	memset(&rsp, 0, sizeof(rsp));
 
 	err = hci_check_conn_params(min, max, latency, to_multiplier);
+	if (!err) {
+		/* Apply local policy only after validating the peer's request. */
+		min = max_t(u16, min, hcon->le_conn_min_interval);
+		max = min_t(u16, max, hcon->le_conn_max_interval);
+		err = hci_check_conn_params(min, max, latency, to_multiplier);
+	}
+
 	if (err)
 		rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
 	else

base-commit: 964430c038967fd06643e866f68115664e1a1bd1

RE: [RFC] Bluetooth: l2cap: honor local LE connection interval range

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1073 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/series/1184338/

---Test result---

Test Summary:
CheckPatch                    PASS      0.60 seconds
VerifyFixes                   PASS      0.08 seconds
VerifySignedoff               PASS      0.08 seconds
GitLint                       PASS      0.24 seconds
SubjectPrefix                 PASS      0.08 seconds
BuildKernel                   PASS      29.43 seconds
CheckAllWarning               PASS      33.15 seconds
CheckSparse                   PASS      35.82 seconds
BuildKernel32                 PASS      29.12 seconds
CheckKernelLLVM               PASS      32.99 seconds
TestRunnerSetup               PASS      699.77 seconds
TestRunner_l2cap-tester       PASS      12.84 seconds
IncrementalBuild              PASS      28.11 seconds



https://github.com/bluez/bluetooth-next/pull/909

---
Regards,
Linux Bluetooth

Re: [RFC PATCH] Bluetooth: l2cap: honor local LE connection interval range

[Luiz Augusto von Dentz]

Hi Kyle,

On Mon, Oct 12, 2026 at 11:31 PM Kyle Pepper <cochcoder@proton.me> wrote:
>
> Intersect a valid peer request with the locally configured interval
> range. Reject disjoint ranges and preserve validation of the original
> request before applying local policy.
>
> Assisted-by: OpenCode:gpt-6.1-sol
> Signed-off-by: Kyle Pepper <cochcoder@proton.me>
> ---
> Submission review notes (not part of the commit message):
> October 12 no-intersection trial accepts [16,24] and completes 30 ms
> with STATUS 03 02 18 and normal host TX; the user hears silence. Volume
> and multi-day acoustic comparison controls are incomplete. The working
> intersection yields 20 ms. Maximum-only rejection failed in kernel 5
> and is not this proposal. Generic minimum/range policy and LL-path
> consistency remain RFC questions, not established by one renderer.

I need to check the git history but I believe we tried something
similar not long ago that created interoperability problems if we use
strict range matching like this.

>  net/bluetooth/l2cap_core.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 49a998804..49e201d3e 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -4968,6 +4968,13 @@ static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
>         memset(&rsp, 0, sizeof(rsp));
>
>         err = hci_check_conn_params(min, max, latency, to_multiplier);
> +       if (!err) {
> +               /* Apply local policy only after validating the peer's request. */
> +               min = max_t(u16, min, hcon->le_conn_min_interval);
> +               max = min_t(u16, max, hcon->le_conn_max_interval);
> +               err = hci_check_conn_params(min, max, latency, to_multiplier);
> +       }
> +
>         if (err)
>                 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
>         else
>
> base-commit: 964430c038967fd06643e866f68115664e1a1bd1
>


-- 
Luiz Augusto von Dentz