From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.sberdevices.ru (mx2.sberdevices.ru [45.89.224.132]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 050581A239D; Wed, 8 Jan 2025 12:39:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.89.224.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736339970; cv=none; b=bOJBy0oj+DcBBPUNfzyQyHv1AZCkVPmWATYFiPTQdA8Od/o8Zs4u0IvjWyi4cBA+0QyTpwVhLgLX5DKGT04UY8t7zdWv9YXptVYj9bl3slQTTE7hi+Enj3ELl0TvGgba4CDh1hGe9TkiBRVjm3/z/cSb3kPfsK/sbIx4y/oxEEA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736339970; c=relaxed/simple; bh=XH9IH6sC5U/ziFuIzuSImom6w0SlRKU/nrd277+5cok=; h=Message-ID:Date:MIME-Version:Subject:From:To:CC:References: In-Reply-To:Content-Type; b=dpvpgZ+dSFYzemvrBAd2HTvOQOik4ySSDjlLPoe5gV8Vje4zZPp9nISyuPHtJCbJwLk5sn5rI2NP+L/cE/br3DVdlpqKA0+RfmsrENyaBmHDS4uXfnCxMEflaMxqJ9MCUiyzK6vml1ASQZcRl6CelvqHQBeB5kHtt7OYFBjAUL8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=salutedevices.com; spf=pass smtp.mailfrom=salutedevices.com; dkim=pass (2048-bit key) header.d=salutedevices.com header.i=@salutedevices.com header.b=BmlC4van; arc=none smtp.client-ip=45.89.224.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=salutedevices.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=salutedevices.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=salutedevices.com header.i=@salutedevices.com header.b="BmlC4van" Received: from p-infra-ksmg-sc-msk02.sberdevices.ru (localhost [127.0.0.1]) by mx1.sberdevices.ru (Postfix) with ESMTP id EC0B5120005; Wed, 8 Jan 2025 15:39:11 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.sberdevices.ru EC0B5120005 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=salutedevices.com; s=mail; t=1736339951; bh=tj6wMZp0GAgUNNfdnRo+2iL01SARqXzeI+FblcEH2hs=; h=Message-ID:Date:MIME-Version:Subject:From:To:Content-Type:From; b=BmlC4vanP7+6Lup+wFyUGVUdVlNy9ZdLzMSsv3Uy0MBziDeqZnXu0ebGvg1z5HQzk xFt6pSIGklc/q5RzX3ucZpBIr2PzfelRuUltYeFeANbYmNI1AUKH6J46CHOmADa1ir Cw35lhRse8w6+B5Dtc3O3wRrnsm2bhdTsWR9wTBWkYGd8aSkccMQgjl28wIT5ToKHU AXMflDwmwviIaMSYeWv4ZPVis0nFgIuGGxnT3W0fWY/kL8prc984b5A5Hkk8bohDxh tGKZJv0eR2r43QY066EqF1xI7y/Yx4kiuGrjJeHJtl6O6BRSXEwSBleYu5dPYU3KIY eYZw4u5S1u2bg== Received: from smtp.sberdevices.ru (p-exch-cas-a-m1.sberdevices.ru [172.24.201.216]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.sberdevices.ru (Postfix) with ESMTPS; Wed, 8 Jan 2025 15:39:11 +0300 (MSK) Message-ID: Date: Wed, 8 Jan 2025 15:39:04 +0300 Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: [PATCH v2] Bluetooth: hci_uart: fix race during initialization Content-Language: en-US From: Arseniy Krasnov To: Luiz Augusto von Dentz CC: Marcel Holtmann , , , , References: In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: p-i-exch-a-m1.sberdevices.ru (172.24.196.116) To p-exch-cas-a-m1.sberdevices.ru (172.24.201.216) X-KSMG-Rule-ID: 1 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Lua-Profiles: 190199 [Jan 08 2025] X-KSMG-AntiSpam-Version: 6.1.1.7 X-KSMG-AntiSpam-Envelope-From: avkrasnov@salutedevices.com X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Info: LuaCore: 49 0.3.49 28b3b64a43732373258a371bd1554adb2caa23cb, {Tracking_from_domain_doesnt_match_to}, smtp.sberdevices.ru:7.1.1,5.0.1;salutedevices.com:7.1.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2, FromAlignment: s X-MS-Exchange-Organization-SCL: -1 X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiPhishing: Clean X-KSMG-LinksScanning: Clean X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.0.1.6960, bases: 2025/01/08 10:11:00 #26958959 X-KSMG-AntiVirus-Status: Clean, skipped On 19.12.2024 23:07, Arseniy Krasnov wrote: > > > On 19.12.2024 22:18, Luiz Augusto von Dentz wrote: >> Hi Arseniy, >> >> On Tue, Dec 17, 2024 at 3:12 AM Arseniy Krasnov >> wrote: >>> >>> 'hci_register_dev()' calls power up function, which is executed by >>> kworker - 'hci_power_on()'. This function does access to bluetooth chip >>> using callbacks from 'hci_ldisc.c', for example 'hci_uart_send_frame()'. >>> Now 'hci_uart_send_frame()' checks 'HCI_UART_PROTO_READY' bit set, and >>> if not - it fails. Problem is that 'HCI_UART_PROTO_READY' is set after >>> 'hci_register_dev()', and there is tiny chance that 'hci_power_on()' will >>> be executed before setting this bit. In that case HCI init logic fails. >>> >>> Patch moves setting of 'HCI_UART_PROTO_READY' before calling function >>> 'hci_uart_register_dev()'. >>> >>> Signed-off-by: Arseniy Krasnov >>> --- >>> Changelog v1->v2: >>> * Move 'set_bit()' before 'hci_uart_register_dev()' instead of >>> adding new bit 'HCI_UART_PROTO_INIT'. >> >> What drivers/controllers this was tested with? I want to make sure >> this doesn't cause regressions to other drivers if there are perhaps >> some drivers assuming HCI_UART_PROTO_READY was set in a certain order. > > Hi, > > I tested this on: > > CONFIG_BT=y > CONFIG_BT_HCIUART=y > CONFIG_BT_HCIUART_H4=y Hi, sorry, but is this enough info about my test env ? Thanks > > Yes, my v1 patchset with extra INIT bit was targeted to keep > original behaviour - e.g. PROTO_READY bit usage still the same, > just adding extra bit to handle this specific case. > > Thanks > >> >>> drivers/bluetooth/hci_ldisc.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c >>> index 30192bb083549..07b9aa09bbe2e 100644 >>> --- a/drivers/bluetooth/hci_ldisc.c >>> +++ b/drivers/bluetooth/hci_ldisc.c >>> @@ -704,12 +704,13 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id) >>> >>> hu->proto = p; >>> >>> + set_bit(HCI_UART_PROTO_READY, &hu->flags); >>> + >>> err = hci_uart_register_dev(hu); >>> if (err) { >>> return err; >>> } >>> >>> - set_bit(HCI_UART_PROTO_READY, &hu->flags); >>> return 0; >>> } >>> >>> -- >>> 2.30.1 >> >> >>