Re: [PATCHv2 7/9] Bluetooth: Use symbolic values for the fixed channel map

[Mat Martineau <mathewm@codeaurora.org>]

On Wed, 19 Oct 2011, Marcel Holtmann wrote:

> Hi Mat,
>
>> The A2MP fixed channel bit is only set when high-speed mode is enabled.
>>
>> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
>> ---
>>  net/bluetooth/l2cap_core.c |    6 +++++-
>>  1 files changed, 5 insertions(+), 1 deletions(-)
>>
>> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
>> index 67f0ab6..f250392 100644
>> --- a/net/bluetooth/l2cap_core.c
>> +++ b/net/bluetooth/l2cap_core.c
>> @@ -60,7 +60,7 @@ int disable_ertm;
>>  int enable_hs;
>>
>>  static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN;
>> -static u8 l2cap_fixed_chan[8] = { 0x02, };
>> +static u8 l2cap_fixed_chan[8] = { L2CAP_FC_L2CAP, };
>>
>>  static LIST_HEAD(chan_list);
>>  static DEFINE_RWLOCK(chan_list_lock);
>> @@ -2975,6 +2975,10 @@ static inline int l2cap_information_req(struct l2cap_conn *conn, struct l2cap_cm
>>  	} else if (type == L2CAP_IT_FIXED_CHAN) {
>>  		u8 buf[12];
>>  		struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
>> +
>> +		if (enable_hs)
>> +			l2cap_fixed_chan[0] |= L2CAP_FC_A2MP;
>> +
>>  		rsp->type   = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
>>  		rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
>>  		memcpy(buf + 4, l2cap_fixed_chan, 8);
>
> doing it this way is a bit sneaky actually. Since it does not really
> allow disabling HS once you enabled it.
>
> Maybe doing feature enabling/disabling (and also for LE) is better
> handled via /sys/kernel/debug/bluetooth/enable_hs.

This is really the only place where anything other than the enable_hs 
value itself needs to be manipulated.  It would be less code to just 
add an "else" and clear the feature mask bit.  l2cap_fixed_chan[] is 
not used anywhere outside this function.

If we want to move enable_hs to debugfs, I'll drop this change from 
patch set and work on debugfs support for the next patch set.

Any other opinions?


--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum