[RFC v2] Bluetooth: Keep master role when SCO or eSCO is active

[RFC v2] Bluetooth: Keep master role when SCO or eSCO is active

[Kiran Kumar Raparthy]

From: "hyungseoung.yoo" <hyungseoung.yoo@samsung.com>

Preserve the master role when SCO or eSCO is active
as this improves compatability with lots of
headset and chipset combinations.

This is one of the number of patches from the Android AOSP
common.git tree, which is used on almost all Android devices.
It looks like it would improve support for compatibility with
lot of headset,so I wanted to submit it for review to see
if it should go upstream.

v2: Fixed formatting issues pointed by Sergei

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-bluetooth@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: hyungseoung.yoo <hyungseoung.yoo@samsung.com>
Signed-off-by: Jaikumar Ganesh <jaikumarg@android.com>
[kiran: Added context to commit message]
Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org>
---
 net/bluetooth/hci_event.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 15010a2..48bc772 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1915,6 +1915,14 @@ unlock:
 	hci_conn_check_pending(hdev);
 }
 
+static inline bool is_sco_active(struct hci_dev *hdev)
+{
+	if (hci_conn_hash_lookup_state(hdev, SCO_LINK, BT_CONNECTED) ||
+		hci_conn_hash_lookup_state(hdev, ESCO_LINK, BT_CONNECTED))
+		return true;
+	return false;
+}
+
 static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_conn_request *ev = (void *) skb->data;
@@ -1961,7 +1969,9 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 			bacpy(&cp.bdaddr, &ev->bdaddr);
 
-			if (lmp_rswitch_capable(hdev) && (mask & HCI_LM_MASTER))
+			if (lmp_rswitch_capable(hdev) &&
+				((mask & HCI_LM_MASTER) ||
+				is_sco_active(hdev)))
 				cp.role = 0x00; /* Become master */
 			else
 				cp.role = 0x01; /* Remain slave */
-- 
1.8.2.1

Re: [RFC v2] Bluetooth: Keep master role when SCO or eSCO is active

[Sergei Shtylyov]

Hello.

On 05/30/2014 10:24 AM, Kiran Kumar Raparthy wrote:

> From: "hyungseoung.yoo" <hyungseoung.yoo@samsung.com>

> Preserve the master role when SCO or eSCO is active
> as this improves compatability with lots of
> headset and chipset combinations.

> This is one of the number of patches from the Android AOSP
> common.git tree, which is used on almost all Android devices.
> It looks like it would improve support for compatibility with
> lot of headset,so I wanted to submit it for review to see
> if it should go upstream.

> v2: Fixed formatting issues pointed by Sergei

> Cc: Marcel Holtmann <marcel@holtmann.org>
> Cc: Gustavo Padovan <gustavo@padovan.org>
> Cc: Johan Hedberg <johan.hedberg@gmail.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: linux-bluetooth@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: Android Kernel Team <kernel-team@android.com>
> Cc: John Stultz <john.stultz@linaro.org>
> Signed-off-by: hyungseoung.yoo <hyungseoung.yoo@samsung.com>
> Signed-off-by: Jaikumar Ganesh <jaikumarg@android.com>
> [kiran: Added context to commit message]
> Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org>
> ---
>   net/bluetooth/hci_event.c | 12 +++++++++++-
>   1 file changed, 11 insertions(+), 1 deletion(-)

> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 15010a2..48bc772 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -1915,6 +1915,14 @@ unlock:
>   	hci_conn_check_pending(hdev);
>   }
>
> +static inline bool is_sco_active(struct hci_dev *hdev)
> +{
> +	if (hci_conn_hash_lookup_state(hdev, SCO_LINK, BT_CONNECTED) ||
> +		hci_conn_hash_lookup_state(hdev, ESCO_LINK, BT_CONNECTED))

    The continuation line should start under the next character after ( on the 
previous line, according to the networking coding style. The way you formatted 
it, it visually groups with the following *return* statement...

> +		return true;
> +	return false;
> +}
> +
>   static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
>   {
>   	struct hci_ev_conn_request *ev = (void *) skb->data;
> @@ -1961,7 +1969,9 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
>
>   			bacpy(&cp.bdaddr, &ev->bdaddr);
>
> -			if (lmp_rswitch_capable(hdev) && (mask & HCI_LM_MASTER))
> +			if (lmp_rswitch_capable(hdev) &&
> +				((mask & HCI_LM_MASTER) ||
> +				is_sco_active(hdev)))

    Same comment.

>   				cp.role = 0x00; /* Become master */
>   			else
>   				cp.role = 0x01; /* Remain slave */

WBR, Sergei