From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balakrishna Godavarthi Subject: Re: [PATCH v1] Bluetooth: hci_qca: Give enough time to ROME controller to bootup. Date: Thu, 07 Mar 2019 12:19:44 +0530 Message-ID: References: <20190306162113.8585-1-bgodavar@codeaurora.org> <155191158734.20095.15990837191526416248@swboyd.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <155191158734.20095.15990837191526416248@swboyd.mtv.corp.google.com> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Boyd Cc: johan.hedberg@gmail.com, marcel@holtmann.org, mka@chromium.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org, rjliao@codeaurora.org List-Id: linux-arm-msm@vger.kernel.org Hi Stepen, On 2019-03-07 04:03, Stephen Boyd wrote: > Quoting Balakrishna Godavarthi (2019-03-06 08:21:13) >> This patch enables enough time to ROME controller to bootup >> after we bring the enable ping out of reset. >> >> Signed-off-by: Balakrishna Godavarthi >> --- > > Any Fixes tag? And maybe some more explanation or background on where > 150 ms sleep comes from would be useful. Was it determined > experimentally or did it come from a datasheet somewhere? Does the time > differ between boards? > [Bala]: this was observed in our stress testing and even the CHIP firmware team confirmed that BT chip required at least 150 ms to boot up. @Rocky to confirm my statement. >> drivers/bluetooth/hci_qca.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c >> index 237aea34b69f..1953b13511e7 100644 >> --- a/drivers/bluetooth/hci_qca.c >> +++ b/drivers/bluetooth/hci_qca.c >> @@ -508,6 +508,8 @@ static int qca_open(struct hci_uart *hu) >> qcadev = serdev_device_get_drvdata(hu->serdev); >> if (qcadev->btsoc_type != QCA_WCN3990) { >> gpiod_set_value_cansleep(qcadev->bt_en, 1); >> + /* Controller needs time to bootup. */ >> + msleep(150); >> } else { >> hu->init_speed = qcadev->init_speed; >> hu->oper_speed = qcadev->oper_speed; -- Regards Balakrishna.