From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12B24C28CF6 for ; Fri, 3 Aug 2018 18:00:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C442D2177F for ; Fri, 3 Aug 2018 18:00:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C442D2177F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729924AbeHCT5m (ORCPT ); Fri, 3 Aug 2018 15:57:42 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:43593 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727356AbeHCT5m (ORCPT ); Fri, 3 Aug 2018 15:57:42 -0400 X-UUID: 08720135f7604b099b391c53db0edc21-20180804 Received: from mtkcas06.mediatek.inc [(172.21.101.30)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 180691104; Sat, 04 Aug 2018 02:00:15 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkexhb01.mediatek.inc (172.21.101.102) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Sat, 4 Aug 2018 02:00:14 +0800 Received: from [172.21.77.33] (172.21.77.33) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1210.3 via Frontend Transport; Sat, 4 Aug 2018 02:00:14 +0800 Message-ID: <1533319214.3472.187.camel@mtkswgap22> Subject: Re: [PATCH v7 2/3] Bluetooth: mediatek: Add protocol support for MediaTek serial devices From: Sean Wang To: Marcel Holtmann CC: Mark Rutland , devicetree , Johan Hedberg , , "open list:BLUETOOTH DRIVERS" , Rob Herring , , linux-arm-kernel Date: Sat, 4 Aug 2018 02:00:14 +0800 In-Reply-To: References: <1707FFA1-A294-4A95-A3BF-0910CE455232@holtmann.org> <1533192799.3472.122.camel@mtkswgap22> <1533199720.3472.136.camel@mtkswgap22> <9526E5D9-50BA-4D57-80F5-083DB7D28AFE@holtmann.org> <1533205495.3472.144.camel@mtkswgap22> <1533303749.3472.160.camel@mtkswgap22> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2018-08-03 at 19:19 +0200, Marcel Holtmann wrote: > Hi Sean, > > >>>>>>>>> + > >>>>>>>>> +static int mtk_hci_wmt_sync(struct hci_dev *hdev, u8 op, u8 flag, u16 plen, > >>>>>>>>> + const void *param) > >>>>>>>>> +{ > >>>>>>>>> + struct mtk_hci_wmt_cmd wc; > >>>>>>>>> + struct mtk_wmt_hdr *hdr; > >>>>>>>>> + struct sk_buff *skb; > >>>>>>>>> + u32 hlen; > >>>>>>>>> + > >>>>>>>>> + hlen = sizeof(*hdr) + plen; > >>>>>>>>> + if (hlen > 255) > >>>>>>>>> + return -EINVAL; > >>>>>>>>> + > >>>>>>>>> + hdr = (struct mtk_wmt_hdr *)&wc; > >>>>>>>>> + hdr->dir = 1; > >>>>>>>>> + hdr->op = op; > >>>>>>>>> + hdr->dlen = cpu_to_le16(plen + 1); > >>>>>>>>> + hdr->flag = flag; > >>>>>>>>> + memcpy(wc.data, param, plen); > >>>>>>>>> + > >>>>>>>>> + atomic_inc(&hdev->cmd_cnt); > >>>>>>>> > >>>>>>>> Why are you doing this one. It will need a comment here if really needed. However I doubt that this is needed. You are only using it from hdev->setup and hdev->shutdown callbacks. > >>>>>>>> > >>>>>>> > >>>>>>> An increment on cmd_cnt is really needed because hci_cmd_work would check whether cmd_cnt is positive and then has a decrement on cmd_cnt before a packet is being sent out. > >>>>>>> > >>>>>>> okay will add a comment. > >>>>>> > >>>>>> but you are in ->setup callback this time. So if you need this, then all the other ->setup routines would actually fail as well. Either this is leftover from when you did things in ->probe or ->open or this is some thing we might better fix properly in the core instead of papering over it. Can you recheck if this is really needed. > >>>>>> > >>>>> > >>>>> I added a counter print and the counter increments as below > >>>>> > >>>>> /* atomic_inc(&hdev->cmd_cnt); */ > >>>>> pr_info("cmd_cnt = %d\n" , atomic_read(&hdev->cmd_cnt)); > >>>>> > >>>>> skb = __hci_cmd_sync_ev(hdev, 0xfc6f, hlen, &wc, HCI_VENDOR_PKT, > >>>>> HCI_INIT_TIMEOUT); > >>>>> > >>>>> and the log show up that > >>>>> > >>>>> > >>>>> [ 334.049156] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 334.054840] cmd_cnt = 0 > >>>>> [ 336.065076] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 336.070795] cmd_cnt = 0 > >>>>> [ 338.080997] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 338.086683] cmd_cnt = 0 > >>>>> [ 340.096907] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 340.102609] cmd_cnt = 0 > >>>>> [ 342.112824] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 342.118520] cmd_cnt = 0 > >>>>> [ 344.128747] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 344.134454] cmd_cnt = 0 > >>>>> [ 346.144667] Bluetooth: hci0: command 0xfc6f tx timeout > >>>>> [ 346.150372] cmd_cnt = 0 > >>>>> > >>>>> > >>>>> The packet is dropped by hci_cmd_work at [1], so I also wondered why the > >>>>> other vendor driver works, it seems the counter needs to be incremented > >>>>> before every skb is being queued to cmd_q. > >>>>> > >>>>> 4257 static void hci_cmd_work(struct work_struct *work) > >>>>> 4258 { > >>>>> 4259 struct hci_dev *hdev = container_of(work, struct hci_dev, cmd_work); > >>>>> 4260 struct sk_buff *skb; > >>>>> 4261 > >>>>> 4262 BT_DBG("%s cmd_cnt %d cmd queued %d", hdev->name, > >>>>> 4263 atomic_read(&hdev->cmd_cnt), skb_queue_len(&hdev->cmd_q)); > >>>>> 4264 > >>>>> 4265 /* Send queued commands */ > >>>>> > >>>>> [1] > >>>>> 4266 if (atomic_read(&hdev->cmd_cnt)) { /* dropped when cmd_cnt is zero */ > >>>>> 4267 skb = skb_dequeue(&hdev->cmd_q); > >>>>> 4268 if (!skb) > >>>>> 4269 return; > >>>>> 4270 > >>>>> 4271 kfree_skb(hdev->sent_cmd); > >>>>> 4272 > >>>>> 4273 hdev->sent_cmd = skb_clone(skb, GFP_KERNEL); > >>>>> 4274 if (hdev->sent_cmd) { > >>>>> 4275 atomic_dec(&hdev->cmd_cnt); /* cmd_cnt-- */ > >>>>> 4276 hci_send_frame(hdev, skb); > >>>> > >>>> actually the command also needs to better go via the raw_q anyway since it doesn’t come back with the cmd status or cmd complete. You have it waiting for a vendor event. Maybe with is something we need to consider with __hci_cmd_sync_ev anyway. > >>>> > >>>> Johan would know best since he wrote that code. Anyway, we should fix that in the core and not have you hack around it. > >>>> > >>> > >>> yes, my case is that received event is neither cmd status nor cmd complete. It is completely a vendor event. > >>> > >>> if it wants to be solved by the core layer, do you permit that I remove the hack and then send it in the next version? > >> > >> we need to have a __hci_raw_sync_ev that uses the hdev->raw_q and waits for the specified event to come back. I never realized that you are missing the cmd status or cmd complete. So this is similar to the original CSR vendor commands which had the same behavior. > >> > >> I have the feeling that you hdev->cmd_cnt increment is just hiding the problem here. If you really think that it is not chains any side effects we can merge the driver with a big warning and fix this up. However the clean way would be for you to create a patch that introduces __hci_raw_sync_ev as describe above. > > > > What do you think of this? If I add extra atomic_set 1 on cmd_cnt after driver really got a vendor event back instead of blinding to increment for every packet sent. > > > > the behavior is the same to receive a cmd status or complete. it should not have side effects. > > > > 96 skb = __hci_cmd_sync_ev(hdev, 0xfc6f, hlen, &wc, HCI_VENDOR_PKT, > > 97 HCI_INIT_TIMEOUT); > > 98 > > 99 if (IS_ERR(skb)) { > > 100 int err = PTR_ERR(skb); > > 101 > > 102 bt_dev_err(hdev, "Failed to send wmt cmd (%d)", err); > > 103 return err; > > 104 } > > 105 > > 106 if (!test_bit(HCI_RESET, &hdev->flags)) <<<<<< > > 107 atomic_set(&hdev->cmd_cnt, 1); <<<<<< > > 108 > > 109 kfree_skb(skb); > > this is even more hackish since the __hci_cmd_sync_ev command is really meant to get a cmd status first before waiting for that event. > Understood. I've stopped the hack in v8. could we merge v8 first ? and then I will a fix up with __hci_raw_sync_ev that uses the hdev->raw_q instead of __hci_cmd_sync_ev in TODO. > Are all Mediatek vendor commands this way? Or just the ones for loading the firmware? So only the WMT ones? > Only the WMT ones, WMT commands/events are usually used in system controlling, for example, global function on/off, firmware download, reset and so on. most only appear on device initialization > Regards > > Marcel > > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek