Return-Path: Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: [PATCH] Bluetooth: btusb: Release RF resource on BT shutdown From: Marcel Holtmann In-Reply-To: Date: Thu, 2 Aug 2018 14:29:59 +0200 Cc: "linux-bluetooth@vger.kernel.org" , "Srivatsa, Ravishankar" Message-Id: References: To: "Bag, Amit K" Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Amit, >>> In case of BT turn off from UI it is safe to add HCI reset command >>> which will maintain the controller state. >> >> this needs to be a bit more details since hdev->shutdown handling is really only for the older Intel controllers. > >> Also I am failing to see why HCI Reset helps or what it does here. It is going to be called again on hdev->open the next time the controller is activated. >> >>> >>> Signed-off-by: Amit K Bag >>> --- >>> drivers/bluetooth/btusb.c | 12 ++++++++++++ >>> 1 file changed, 12 insertions(+) >>> >>> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c >>> index 572fd75fbcf6..599ec9b12d3f 100644 >>> --- a/drivers/bluetooth/btusb.c >>> +++ b/drivers/bluetooth/btusb.c >>> @@ -2369,6 +2369,18 @@ static int btusb_shutdown_intel(struct hci_dev *hdev) >>> struct sk_buff *skb; >>> long ret; >>> >>> + /* In case of BT off from UI it is safe to do HCI reset. >>> + * This will maintain the controller state. >>> + */ >> >> I do not care what the UI does here. This is power down operation and so it needs to be explained properly. And with a lot more details since I am failing to understand what state is maintained on HCI Reset. As per specification it will reset all Bluetooth > > states back to the defaults. >> >>> + skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL, HCI_INIT_TIMEOUT); >>> + if (IS_ERR(skb)) { >>> + ret = PTR_ERR(skb); >>> + BT_ERR("%s: BT controller HCI reset failed (%ld)", >>> + hdev->name, ret); >>> + return ret; >>> + } >>> + kfree_skb(skb); >>> + >> >>> There is whitespace damage here. And if this hasn’t been done yet, please first start using bt_dev_err instead of BT_ERR for the Intel parts. >> >>> /* Some platforms have an issue with BT LED when the interface is >>> * down or BT radio is turned off, which takes 5 seconds to BT LED >>> * goes off. This command turns off the BT LED immediately. >> >> Regards >> >> Marcel > > > I have updated the patch as per your comments. Please find the patch as below. > > Issue description: Intel 2765 shares the same RF with Wifi and BT. 7265 ? > In the shutdown scenario turn off BT, followed by turn WiFi off > and on causing error in RF calibration in WiFi Module > > Solution: before shutdown BT ensure any RF activity to clear by > HCI reset command. > > Reference Logs: > ERR kernel: [ 386.193284] iwlwifi 0000:01:00.0: Failed to run INIT calibrations: -5 > ERR kernel: [ 386.193298] iwlwifi 0000:01:00.0: Failed to run INIT ucode: -5 > ERR kernel: [ 386.193309] iwlwifi 0000:01:00.0: Failed to start RT ucode: -5 > > Signed-off-by: Amit K Bag > --- > drivers/bluetooth/btusb.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c > index 572fd75fbcf6..4a3b6a7dc86f 100644 > --- a/drivers/bluetooth/btusb.c > +++ b/drivers/bluetooth/btusb.c > @@ -2369,6 +2369,21 @@ static int btusb_shutdown_intel(struct hci_dev *hdev) > struct sk_buff *skb; > long ret; > > + /* ISSUE: In shutdown sequence where BT turn off and followed Scrap the word ISSUE: since that is not needed. Just describe why we are doing this. > + * by WiFi turn off, and if Wifi is turn on back, Wifi is unable > + * to do the RF calibration.(observe this on INTEL 7265) No need for the text in () > + * > + * Solution: before shutdown BT ensure any RF activity to clear > + * by send this command. > + */ Scrap the Solution: and bring this in as proper sentence. > + skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL, HCI_INIT_TIMEOUT); > + if (IS_ERR(skb)) { > + ret = PTR_ERR(skb); > + bt_dev_err(hdev, "%s: HCI reset failed\n", __func__); Scrap the __func__ usage. We are not doing this. Also no \n with the bt_dev_err. If you want this clear then "HCI reset on shutdown failed”. > + return ret; > + } > + kfree_skb(skb); > + > /* Some platforms have an issue with BT LED when the interface is > * down or BT radio is turned off, which takes 5 seconds to BT LED > * goes off. This command turns off the BT LED immediately. Regards Marcel