[Dev] Anyone know what this is?

Jorge Ramirez-Ortiz jorge.ramirez-ortiz at linaro.org
Fri Apr 17 11:25:30 UTC 2015


On 04/17/2015 04:37 AM, Daniel Thompson wrote:
> On 17/04/15 02:58, Jorge Ramirez-Ortiz wrote:
>> On 04/16/2015 08:58 PM, Scott Bambrough wrote:
>>> BT works, I get this on 258, 260 -- hadn't seen it before.
>>
>> it means that BT is taken longer to initialize - ie: user space (UIM) is taking
>> longer to run measured from the time the btwilink.ko is modprobed by udev.
>
> Forgive my interfering but I'm not sure all this comes from userspace
> (although the cause could be in userspace).

please everyone more than welcome to interfere.

>
> I had a look at the ti driver code earlier in the week and first four messages
> looked to me like a failure to get the TI device into firmware loading mode.

yes - well kind of.

when the driver is loaded, st_kim_start waits for the line discipline to be
installed.
[0]https://github.com/96boards/linux/blob/hikey/drivers/misc/ti-st/st_kim.c#L461


the completion is waiting for is usermode opening the tty[1] and the completion
being executed (from st_tty_open) [2]
[1] https://github.com/96boards/uim/blob/master/uim.c#L289
[2] https://github.com/96boards/linux/blob/hikey/drivers/misc/ti-st/st_core.c#L702

once opened, the line discipline is installed and the firmarware version present
in the device is read at dhe default settings (115kbps)
The driver reads "TIInit_11.8.32.bts" - meaning the that device is accessible
and healthy.

After this has happened, usermode then takes control (UIM) and changes the baud
rate command in the firmware to the value presented by the device tree to the
user via sysfs.
https://github.com/96boards/uim/blob/master/uim.c#L356

this is done by sending 0xFF36 opcode (see here):
https://github.com/96boards/uim/blob/master/uim.c#L356

and I think this is pretty much what is happening.


>
> <speculation based-on="absolutely-no-evidence-at-all">
> I wondered if the driver had ended up probing something with nothing connected
> to it.
> </speculation>
>
> Either way the timeout for both install/uninstall mean that it's taking two
> (elapsed) seconds longer than it should to complete the operation.
>
>
> Daniel.
>
>
>>>
>>> Scott
>>>
>>> On Tue, Apr 14, 2015 at 12:29 PM, Jorge Ramirez-Ortiz <
>>> jorge.ramirez-ortiz at linaro.org> wrote:
>>>
>>>> On 04/14/2015 12:16 PM, Scott Bambrough wrote:
>>>>> [   97.961005] (stk) :ldisc_install = 1
>>>>> [   98.953839] (stk) :ldisc installation timeout
>>>>> [   98.958592] (stk) :ldisc_install = 0
>>>>> [   99.953743] (stk) : timed out waiting for ldisc to be un-installed
>>>>> [  100.067870] (stk) :ldisc_install = 1
>>>>> [  100.254135] (stc): st_tty_open
>>>>> [  100.254253] (stk) :line discipline installed
>>>>> [  100.254762] (stk) :ti-connectivity/TIInit_11.8.32.bts
>>>>> [  101.383101] (stk) :change remote baud rate command in firmware
>>>>> [  101.383125] (stk) :skipping the wait event of change remote baud
>>>>>
>>>>> I was seeing it in the 258 developer image and now in 259 alip image.
>>>>>
>>>> This is the Bluetooth initialization - there is a time dependency from the
>>>> moment the module is inserted to the UIM completing the sequence but there
>>>> doesnt seem to be any errors
>>>> Does BT work for you?
>>>>
>>>> I still need to check this message though:
>>>>
>>>> [  101.383125] (stk) :skipping the wait event of change remote baud
>>>>
>>>>
>>>>
>>>>
>>>
>>
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>
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