Skip to contentSkip to conversation

Simultaneous data transfer on ACL and BLE links

DISCUSSION Ajay 1 participant 1 message Jan 21, 2013 Bluetooth drivers

lore
Share & tools
lore

Ajay

author
#0 lore raw

Hi ,
Kernel has set some restrictions in simultaneous L2cap data
transfer on BLE and ACL links on a common device .

My test scenario is as follows
Device A has both LE and ACL link with device B and C
respectively . when i start sending l2cap data on ACL link (A to B), it work fine . But when i starts sending BLE data along with ACL data (A to C ) , it fails with error "send failed : interrupt system call" . when i count the LE packets that had reached upto hci layer , it shows some 367 packets.
Later i noticed that LE data is getting queued at hci
layer and it is not scheduled properly . following piece of code tells us the order of scheduling.. (hci_core.c)

static void hci_tx_task(unsigned long arg)

{
    struct hci_dev *hdev = (struct hci_dev *) arg;
    struct sk_buff *skb;

    read_lock(&hci_task_lock);

    BT_DBG("%s acl %d sco %d le %d", hdev->name, hdev->acl_cnt,
        hdev->sco_cnt, hdev->le_cnt);

    /* Schedule queues and send stuff to HCI driver */

    hci_sched_acl(hdev);

    hci_sched_sco(hdev);

    hci_sched_esco(hdev);

    hci_sched_le(hdev);

......

Here both acl and le scheduling are using same count as
reference (hdev->acl_cnt) and they have never make use of hdev->le_cnt.

please kindly go through this issue.

Signature · 5 lines
Thanks & Regards

 AJAY KV
 GlobalEdge software Ltd
 8892753703

begin:vcard
fn:AJAY KV
n:;AJAY
tel;cell:8892753703
version:2.1
end:vcard