[PATCH] Bluetooth: btrsi: fix bt tx timeout issue

[PATCH] Bluetooth: btrsi: fix bt tx timeout issue

[Siva Rebbagondla]

From: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>

observed sometimes data is coming with unaligned address from kernel
BT stack. If unaligned address is passed, some data in payload is
stripped when packet is loading to firmware and this results, BT
connection timeout is happening.

sh# hciconfig hci0 up
Can't init device hci0: hci0 command 0x0c03 tx timeout

Fixed this by moving the data to aligned address.

Signed-off-by: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>
Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
---
 drivers/bluetooth/btrsi.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btrsi.c b/drivers/bluetooth/btrsi.c
index 60d1419..3951f7b 100644
--- a/drivers/bluetooth/btrsi.c
+++ b/drivers/bluetooth/btrsi.c
@@ -21,8 +21,9 @@
 #include <net/rsi_91x.h>
 #include <net/genetlink.h>
 
-#define RSI_HEADROOM_FOR_BT_HAL	16
+#define RSI_DMA_ALIGN	8
 #define RSI_FRAME_DESC_SIZE	16
+#define RSI_HEADROOM_FOR_BT_HAL	(RSI_FRAME_DESC_SIZE + RSI_DMA_ALIGN)
 
 struct rsi_hci_adapter {
 	void *priv;
@@ -70,6 +71,16 @@ static int rsi_hci_send_pkt(struct hci_dev *hdev, struct sk_buff *skb)
 		bt_cb(new_skb)->pkt_type = hci_skb_pkt_type(skb);
 		kfree_skb(skb);
 		skb = new_skb;
+		if (!IS_ALIGNED((unsigned long)skb->data, RSI_DMA_ALIGN)) {
+			u8 *skb_data = skb->data;
+			int skb_len = skb->len;
+
+			skb_push(skb, RSI_DMA_ALIGN);
+			skb_pull(skb, PTR_ALIGN(skb->data,
+						RSI_DMA_ALIGN) - skb->data);
+			memmove(skb->data, skb_data, skb_len);
+			skb_trim(skb, skb_len);
+		}
 	}
 
 	return h_adapter->proto_ops->coex_send_pkt(h_adapter->priv, skb,
-- 
2.7.4

Re: [PATCH] Bluetooth: btrsi: fix bt tx timeout issue

[Siva Rebbagondla]

On Wed, Aug 29, 2018 at 2:24 PM Siva Rebbagondla <siva8118@gmail.com> wrote:
>
> From: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>
>
> observed sometimes data is coming with unaligned address from kernel
> BT stack. If unaligned address is passed, some data in payload is
> stripped when packet is loading to firmware and this results, BT
> connection timeout is happening.
>
> sh# hciconfig hci0 up
> Can't init device hci0: hci0 command 0x0c03 tx timeout
>
> Fixed this by moving the data to aligned address.
>
> Signed-off-by: Sanjay Kumar Konduri <sanjay.konduri@redpinesignals.com>
> Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
> ---
>  drivers/bluetooth/btrsi.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/btrsi.c b/drivers/bluetooth/btrsi.c
> index 60d1419..3951f7b 100644
> --- a/drivers/bluetooth/btrsi.c
> +++ b/drivers/bluetooth/btrsi.c
> @@ -21,8 +21,9 @@
>  #include <net/rsi_91x.h>
>  #include <net/genetlink.h>
>
> -#define RSI_HEADROOM_FOR_BT_HAL        16
> +#define RSI_DMA_ALIGN  8
>  #define RSI_FRAME_DESC_SIZE    16
> +#define RSI_HEADROOM_FOR_BT_HAL        (RSI_FRAME_DESC_SIZE + RSI_DMA_ALIGN)
>
>  struct rsi_hci_adapter {
>         void *priv;
> @@ -70,6 +71,16 @@ static int rsi_hci_send_pkt(struct hci_dev *hdev, struct sk_buff *skb)
>                 bt_cb(new_skb)->pkt_type = hci_skb_pkt_type(skb);
>                 kfree_skb(skb);
>                 skb = new_skb;
> +               if (!IS_ALIGNED((unsigned long)skb->data, RSI_DMA_ALIGN)) {
> +                       u8 *skb_data = skb->data;
> +                       int skb_len = skb->len;
> +
> +                       skb_push(skb, RSI_DMA_ALIGN);
> +                       skb_pull(skb, PTR_ALIGN(skb->data,
> +                                               RSI_DMA_ALIGN) - skb->data);
> +                       memmove(skb->data, skb_data, skb_len);
> +                       skb_trim(skb, skb_len);
> +               }
>         }
>
>         return h_adapter->proto_ops->coex_send_pkt(h_adapter->priv, skb,
> --
> 2.7.4
>
Kindly ignore this.
Instead of adding linux-kernel@vger.kernel.org, I have added
linux-wireless@vger.kernel.org, which results, this
patch is showing in linux-wireless patch work.
I will resend this patch by removing, "linux-wireless" from mailing list.

Thanks,
Siva Rebbagondla.