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Message-ID: <e132145c-0da9-4b2d-aba8-5d02690a5fee@molgen.mpg.de>
Date: Wed, 22 May 2024 13:22:04 +0200
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Subject: Re: [PATCH] Bluetooth: vendor specific ISO data packet identification
 by handle
To: Ying Hsu <yinghsu@chromium.org>
Cc: chromeos-bluetooth-upstreaming@chromium.org,
 Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
 Marcel Holtmann <marcel@holtmann.org>, linux-bluetooth@vger.kernel.org,
 linux-kernel@vger.kernel.org
References: <20240522111139.2612601-1-yinghsu@chromium.org>
Content-Language: en-US
From: Paul Menzel <pmenzel@molgen.mpg.de>
In-Reply-To: <20240522111139.2612601-1-yinghsu@chromium.org>
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Dear Ying,


Thank you for your patch. Some minor comments.

Could you please make the summary/title a statement by using a verb (in 
imperative mood).

Am 22.05.24 um 13:11 schrieb Ying Hsu:
> When HCI raw sockets are opened, the Bluetooth kernel module doesn't
> track CIS/BIS connections. User-space applications have to identify
> ISO data by maintaining connection information and look up the mapping
> for each ACL data packet received. Besides, btsnoop log catpured in

captured

> kernel would couldn't tell ISO data from ACL data in this case.

Excessive *would*?

> By differentiating ISO data from ACL data earlier in btusb, we can
> eliminate unnecessary lookups and improve btsnoop log clarity.
> This patch enables vendor-specific differentiation between ISO and
> ACL data packets.

Make it clear, that this is only done for Intel devices?

> Signed-off-by: Ying Hsu <yinghsu@chromium.org>
> ---
> Tested LE unicast recording on a ChromeOS device with Intel AX211

I’d add that to the commit message, and also name the exact device name 
you used.

>   drivers/bluetooth/btusb.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 79aefdb3324d..543961b6c671 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -889,6 +889,8 @@ struct btusb_data {
>   	int (*recv_acl)(struct hci_dev *hdev, struct sk_buff *skb);
>   	int (*recv_bulk)(struct btusb_data *data, void *buffer, int count);
>   
> +	int (*is_iso_data_pkt)(struct sk_buff *skb);
> +
>   	int (*setup_on_usb)(struct hci_dev *hdev);
>   
>   	int oob_wake_irq;   /* irq for out-of-band wake-on-bt */
> @@ -1229,6 +1231,8 @@ static int btusb_recv_bulk(struct btusb_data *data, void *buffer, int count)
>   
>   		if (!hci_skb_expect(skb)) {
>   			/* Complete frame */
> +			if (data->is_iso_data_pkt && data->is_iso_data_pkt(skb))
> +				hci_skb_pkt_type(skb) = HCI_ISODATA_PKT;
>   			btusb_recv_acl(data, skb);
>   			skb = NULL;
>   		}
> @@ -2539,6 +2543,13 @@ static int btusb_recv_bulk_intel(struct btusb_data *data, void *buffer,
>   	return btusb_recv_bulk(data, buffer, count);
>   }
>   
> +static int btusb_is_iso_data_pkt_intel(struct sk_buff *skb)

Why not return `bool`?

> +{
> +	__u16 handle = (__le16_to_cpu(hci_acl_hdr(skb)->handle) & 0xfff);
> +
> +	return (handle >= 0x900);

Define a macro?

> +}
> +
>   static int btusb_send_frame_intel(struct hci_dev *hdev, struct sk_buff *skb)
>   {
>   	struct urb *urb;
> @@ -4361,6 +4372,9 @@ static int btusb_probe(struct usb_interface *intf,
>   		/* Override the rx handlers */
>   		data->recv_event = btintel_recv_event;
>   		data->recv_bulk = btusb_recv_bulk_intel;
> +
> +		/* Override for ISO data packet*/

Please add a space before */.

> +		data->is_iso_data_pkt = btusb_is_iso_data_pkt_intel;
>   	} else if (id->driver_info & BTUSB_REALTEK) {
>   		/* Allocate extra space for Realtek device */
>   		priv_size += sizeof(struct btrealtek_data);