From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 54EEF5683 for ; Mon, 3 Apr 2023 14:19:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D08D6C433D2; Mon, 3 Apr 2023 14:19:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680531562; bh=i2GGW3Zzb33Agi4Dth8sraYtXMV8E2zOCVJOmTcxFCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E2XnrImn0KnAavQovVXdMGTN37vBLfpD5Ubtwad80oIsb8Lg7OHZvCB22DDr5X9RO k1vm7lyME6mtCfy0zv5QKGLSC61OstDDrM6LdqnkVHzhm4rkiOsgngdekYcouW7PV4 aDi6l+DoziWGdLfMJCqPjfB0/OhwZ8tELlDmLpeI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stephan Gerhold , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 5.4 025/104] Bluetooth: btqcomsmd: Fix command timeout after setting BD address Date: Mon, 3 Apr 2023 16:08:17 +0200 Message-Id: <20230403140405.250997865@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140403.549815164@linuxfoundation.org> References: <20230403140403.549815164@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Stephan Gerhold [ Upstream commit 5d44ab9e204200a78ad55cdf185aa2bb109b5950 ] On most devices using the btqcomsmd driver (e.g. the DragonBoard 410c and other devices based on the Qualcomm MSM8916/MSM8909/... SoCs) the Bluetooth firmware seems to become unresponsive for a while after setting the BD address. On recent kernel versions (at least 5.17+) this often causes timeouts for subsequent commands, e.g. the HCI reset sent by the Bluetooth core during initialization: Bluetooth: hci0: Opcode 0x c03 failed: -110 Unfortunately this behavior does not seem to be documented anywhere. Experimentation suggests that the minimum necessary delay to avoid the problem is ~150us. However, to be sure add a sleep for > 1ms in case it is a bit longer on other firmware versions. Older kernel versions are likely also affected, although perhaps with slightly different errors or less probability. Side effects can easily hide the issue in most cases, e.g. unrelated incoming interrupts that cause the necessary delay. Fixes: 1511cc750c3d ("Bluetooth: Introduce Qualcomm WCNSS SMD based HCI driver") Signed-off-by: Stephan Gerhold Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- drivers/bluetooth/btqcomsmd.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/bluetooth/btqcomsmd.c b/drivers/bluetooth/btqcomsmd.c index 2acb719e596f5..11c7e04bf3947 100644 --- a/drivers/bluetooth/btqcomsmd.c +++ b/drivers/bluetooth/btqcomsmd.c @@ -122,6 +122,21 @@ static int btqcomsmd_setup(struct hci_dev *hdev) return 0; } +static int btqcomsmd_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr) +{ + int ret; + + ret = qca_set_bdaddr_rome(hdev, bdaddr); + if (ret) + return ret; + + /* The firmware stops responding for a while after setting the bdaddr, + * causing timeouts for subsequent commands. Sleep a bit to avoid this. + */ + usleep_range(1000, 10000); + return 0; +} + static int btqcomsmd_probe(struct platform_device *pdev) { struct btqcomsmd *btq; @@ -162,7 +177,7 @@ static int btqcomsmd_probe(struct platform_device *pdev) hdev->close = btqcomsmd_close; hdev->send = btqcomsmd_send; hdev->setup = btqcomsmd_setup; - hdev->set_bdaddr = qca_set_bdaddr_rome; + hdev->set_bdaddr = btqcomsmd_set_bdaddr; ret = hci_register_dev(hdev); if (ret < 0) -- 2.39.2