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Bluetooth: Only schedule LE tx links if LE-capable

RFC In review Peter Hurley 4 participants 6 messages Aug 18, 2011 – Aug 19, 2011 1 message not in the archive Bluetooth drivers

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Peter Hurley

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#0 lore raw

RFC v2 1/5 Bluetooth: Only schedule LE tx links if LE-capable

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maintainer
#1 lore raw

Hi Peter,

Quoted 24 lines · Peter Hurley

Only perform tx scheduling for LE links if the host controller is LE-capable.

Signed-off-by Peter Hurley <[email protected]>

---
 net/bluetooth/hci_core.c |    4 +++-

 1 files changed, 3 insertions(+), 1 deletions(-)
net/bluetooth/hci_core.c +3 -2
index 815269b..47a31fa 100644
@@ -1995,7 +1995,9 @@ static void hci_tx_task(unsigned long arg)
 
        hci_sched_esco(hdev);
 
-       hci_sched_le(hdev);
+       /* Only schedule le links if device is le-capable */
+       if (lmp_le_capable(hdev))
+               hci_sched_le(hdev);
 
        /* Send next queued raw (unknown type) packet */
        while ((skb = skb_dequeue(&hdev->raw_q)))
--
Quoted 3 lines

1.7.4.1

Any reasons why you choose to not add the check inside hci_sched_le?

Signature · 1 line
Luiz Augusto von Dentz

A message that is not in the archive (sent off-list or not yet received): 1313666245.17513.9.camel@THOR

#3 lore raw

Hi Peter,

Quoted 5 lines · Peter Hurley
Quoted 1 line · Luiz Augusto von Dentz

Any reasons why you choose to not add the check inside hci_sched_le?

Only to make it really obvious that LE transmission is not required on the vast majority of BT controllers :)

... yet. Are you aware LE is not optional on Bluetooth 4.0? Therefore any modern BT device claiming to support 4.0 will have LE support on its controller (host support is another thing).

But I suppose we will still see plenty of 2.1 devices for a long time...

My two cents,

Signature · 3 lines
Anderson Lizardo
Instituto Nokia de Tecnologia - INdT
Manaus - Brazil
author
#4 lore raw

Hi Anderson,

Quoted 4 lines · Anderson Lizardo

Hi Peter,

Quoted 1 line · Peter Hurley

On Thu, 2011-08-18 at 03:43 -0400, Luiz Augusto von Dentz wrote:

Quoted 8 lines
Quoted 4 lines
Quoted 1 line

Any reasons why you choose to not add the check inside hci_sched_le?

Only to make it really obvious that LE transmission is not required on the vast majority of BT controllers :)

... yet. Are you aware LE is not optional on Bluetooth 4.0? Therefore any modern BT device claiming to support 4.0 will have LE support on its controller (host support is another thing).

I was aware of that, but that's an important point you make.

Quoted 1 line

But I suppose we will still see plenty of 2.1 devices for a long time...

As I noted to Andre earlier, this particular test will be unnecessary when Luiz's proposal (using the LE connection count to bypass LE scheduling when 0). I feel Luiz's approach is the more effective approach anyway.

Regards,
Peter Hurley

#5 lore raw
In reply to Peter Hurley

Hi Peter,

Quoted 13 lines · Peter Hurley

Only perform tx scheduling for LE links if the host controller is LE-capable.

Signed-off-by Peter Hurley <[email protected]>

---
net/bluetooth/hci_core.c | 4 +++-

1 files changed, 3 insertions(+), 1 deletions(-)
net/bluetooth/hci_core.c +0 -0
index 815269b..47a31fa 100644

net/bluetooth/hci_core.c static void hci_tx_task(unsigned long arg) · line 2000

Quoted 7 lines
net/bluetooth/hci_core.c +3 -1
@@ -1995,7 +1995,9 @@ static void hci_tx_task(unsigned long arg)
 
 	hci_sched_esco(hdev);
 
-	hci_sched_le(hdev);
+	/* Only schedule le links if device is le-capable */
+	if (lmp_le_capable(hdev))
+		hci_sched_le(hdev);

You may use lmp_host_le_capable macro here since it tells you if the _host_ supports LE (lmp_le_capable macro tells you if the _controller_ supports LE).

BR,
Andre

author
#6 lore raw

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