Hi, Marcel
On Tue, 2018-05-08 at 09:27 +0200, Marcel Holtmann wrote:
> Hi Sean,
>
> >>> +
> >>> +static int mtk_wmt_cmd_sync(struct hci_uart *hu, u8 opcode, u8 flag, u16
> >>> plen,
> >>> + const void *param)
> >>> +{
> >>> + struct mtk_bt_dev *btdev = hu->priv;
> >>> + struct hci_command_hdr *hhdr;
> >>> + struct hci_acl_hdr *ahdr;
> >>> + struct mtk_wmt_hdr *whdr;
> >>> + struct sk_buff *skb;
> >>> + int ret = 0;
> >>> +
> >>> + init_completion(&btdev->wmt_cmd);
> >>> +
> >>> + skb = bt_skb_alloc(plen + MTK_WMT_CMD_SIZE, GFP_KERNEL);
> >>> + if (!skb)
> >>> + return -ENOMEM;
> >>> +
> >>> + /*
> >>> + * WMT data is carried in either ACL or HCI format with op code as
> >>> + * 0xfc6f and followed by a WMT header and its actual payload.
> >>> + */
> >>
> >> Please use net subsystem comment style.
> >>
> >>> + switch (opcode) {
> >>> + case MTK_WMT_PATCH_DWNLD:
> >>> + ahdr = skb_put(skb, HCI_ACL_HDR_SIZE);
> >>> + ahdr->handle = cpu_to_le16(0xfc6f);
> >>> + ahdr->dlen = cpu_to_le16(plen + MTK_WMT_HDR_SIZE);
> >>> + break;
> >>> + default:
> >>> + hhdr = skb_put(skb, HCI_COMMAND_HDR_SIZE);
> >>> + hhdr->opcode = cpu_to_le16(0xfc6f);
> >>> + hhdr->plen = plen + MTK_WMT_HDR_SIZE;
> >>> + break;
> >>> + }
> >>> +
> >>> + hci_skb_pkt_type(skb) = opcode == MTK_WMT_PATCH_DWNLD ?
> >>> + HCI_ACLDATA_PKT : HCI_COMMAND_PKT;
> >>
> >> Why not move that into the switch statement above.
> >>
> >>> +
> >>> + /* Start to build a WMT header and its actual payload. */
> >>> + whdr = skb_put(skb, MTK_WMT_HDR_SIZE);
> >>> + whdr->dir = 1;
> >>> + whdr->op = opcode;
> >>> + whdr->dlen = cpu_to_le16(plen + 1);
> >>> + whdr->flag = flag;
> >>> + skb_put_data(skb, param, plen);
> >>> +
> >>> + mtk_enqueue(hu, skb);
> >>> + hci_uart_tx_wakeup(hu);
> >>> +
> >>> + /*
> >>> + * Waiting a WMT event response, while we must take care in case of
> >>> + * failures for the wait.
> >>> + */
> >>> + ret = wait_for_completion_interruptible_timeout(&btdev->wmt_cmd, HZ);
> >>> +
> >>> + return ret > 0 ? 0 : ret < 0 ? ret : -ETIMEDOUT;
> >>> +}
> >>
> >> All in all I am not convinced that this is super clean. I get that we need
> >> something special for having this in the ACL data packets, but for the
> >> standard HCI command I prefer that __hci_cmd_sync is used. I addition, it
> >> seems that patch download is the only special case and that happens before
> >> at the setup stage. So we could make things special for that. I need to
> >> understand this a bit better. Can I get a btmon -w trace.log file from the
> >> whole init procedure.
> >>
> >
> > While i was trying to rewrite the driver based on btuart.c. you posted
> > on RFC, I used __hci_cmd_sync_ev to replace such kinds of SoC specific
> > hci command sending which I've done previously with mtk_wmt_cmd_sync.
> >
> > However, eventually, I got a cmd_timer timeout whose message printed
> > on console as "Bluetooth: hci0: command 0xfc6f tx timeout".
> >
> > The mtk soc specific cmd/event I posted below, I dumped directly in
> > driver, always uses cmd as opcode 0xfc6f, and its event id as 0xe4.
> >
> > It appears to the event id is not standard and thus it cannot cancel the
> > cmd timer when the special hci event is being handled. This way can we
> > can still use __hci_cmd_sync api ?
> >
> > [ 4.896200] hci tx: 00000000: 01 6f fc 05 01 07 01 00 04
> > [ 4.904671] hci rx: 00000000: e4 05 02 07 01 00
> > 00
> > [ 4.912859] Bluetooth: hci0 event 0xe4
> >
> >
> > buildroot login: [ 6.914509] Bluetooth: hci0: command 0xfc6f tx
> > timeout
> > [ 6.919831] hci tx: 00000000: 01 6f fc 06 01 06 02 00 00
> > 01 .o........
> > [ 7.006631] hci rx: 00000000: e4 05 02 06 01 00
> > 00 .......
> > [ 7.014821] Bluetooth: hci0 event 0xe4
>
> can you just start btmon before loading the module / driver? It makes it a
> lot easier since it will actually decode the basics for us. If there is a bug
> within __hci_cmd_sync_ev, then we are going to fix it.
>
I'm happy to do with btmon. just the environment with buildroot the BT
running on seems there's a missing support for btmon. I can start to use
btmon once I change the environment to Debian.
> So all the MTK vendor commands respond with a vendor event? Or are there some
> that do the standard command status/complete handling?
>
yes, mtk controller after mt7622 (included), its MTK vendors command
(opcode 0xfc6f) always respond with a vendor event id 0xe4. And they
don't do any standard status/complete handling.
BTW, mtk controller before mt7622, such as mt7623, its MTK vendor
command always go with completely specific format, not with hci format.
> Regards
>
> Marcel
>
