Message-ID: <bc5ba838-ecf6-f5c8-e6bf-312ce7077911@gentil.com>
Date:   Sun, 5 Mar 2023 17:28:38 -0800
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To:     linux-bluetooth@vger.kernel.org
From:   Gregoire Gentil <gregoire@gentil.com>
Subject: How can I change the supervision timeout of BLE peripheral?
Organization: Gregoire Gentil
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Hello,

I have a pure C application running on a BLE peripheral and it uses 
bluez code especially the code base of hcitool.

In le_set_advertising_parameters_cp, I see min_interval and max_interval 
but I don't see any supervision timeout field. Is there another 
advertising parameters (extended???) that features supervision timeout?

I'm aware of the following code in hcitool:

hci_write_link_supervision_timeout(device_handle, 
htobs(cr->conn_info->handle), timeout, 1000);

But in my own code, I don't manage to get the handle of the central 
device once the connection has been established - I'm also wondering 
whether if it's not too late to change supevision timeout after the 
connection. "ioctl(device_handle, HCIGETCONNINFO, (unsigned long) cr);" 
fails with a "no such file or directory" error though I'm sure that the 
central device is connected.


How can I change from user-space the supervision timeout?

Thank you in advance,

Grégoire