Return-Path: Message-ID: <1525767775.18877.22.camel@mtkswgap22> Subject: Re: [PATCH v1 6/7] Bluetooth: hci_mediatek: Add protocol support for MediaTek serial devices From: Sean Wang To: Marcel Holtmann CC: Rob Herring , Mark Rutland , Johan Hedberg , devicetree , BlueZ development , linux-arm-kernel , , Date: Tue, 8 May 2018 16:22:55 +0800 In-Reply-To: References: <1525762084.14468.20.camel@mtkswgap22> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 List-ID: 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 >