From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: Re: [PATCH v3 1/4] Bluetooth: hci_qca: use wait_until_sent() for power pulses Date: Wed, 5 Dec 2018 07:25:03 +0100 Message-ID: <20181205062503.GG18087@localhost> References: <20181130150247.26294-1-bgodavar@codeaurora.org> <20181130150247.26294-2-bgodavar@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20181130150247.26294-2-bgodavar@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Balakrishna Godavarthi Cc: marcel@holtmann.org, johan.hedberg@gmail.com, mka@chromium.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org On Fri, Nov 30, 2018 at 08:32:44PM +0530, Balakrishna Godavarthi wrote: > wcn3990 requires a power pulse to turn ON/OFF along with > regulators. Sometimes we are observing the power pulses are sent > out with some time delay, due to queuing these commands. This is > causing synchronization issues with chip, which intern delay the > chip setup or may end up with communication issues. > > Signed-off-by: Balakrishna Godavarthi > --- > v3: > * no change. > v2: > * Updated function qca_send_power_pulse() > * addressed reviewer comments. Please make sure to include reviewers on CC when resending, and as someone else already mentioned, be a bit more specific about what changes you actually made in response to the review feedback you received. > v1: > * initial patch > --- > drivers/bluetooth/hci_qca.c | 37 +++++++++++++------------------------ > 1 file changed, 13 insertions(+), 24 deletions(-) > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index f036c8f98ea3..f5dd323c1967 100644 > --- a/drivers/bluetooth/hci_qca.c > +++ b/drivers/bluetooth/hci_qca.c > @@ -1013,11 +1013,9 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed) > hci_uart_set_baudrate(hu, speed); > } > > -static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd) > +static int qca_send_power_pulse(struct hci_uart *hu, u8 cmd) > { > - struct hci_uart *hu = hci_get_drvdata(hdev); > - struct qca_data *qca = hu->priv; > - struct sk_buff *skb; > + int ret; > > /* These power pulses are single byte command which are sent > * at required baudrate to wcn3990. On wcn3990, we have an external > @@ -1029,19 +1027,16 @@ static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd) > * save power. Disabling hardware flow control is mandatory while > * sending power pulses to SoC. > */ > - bt_dev_dbg(hdev, "sending power pulse %02x to SoC", cmd); > - > - skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL); > - if (!skb) > - return -ENOMEM; > - > + bt_dev_dbg(hu->hdev, "sending power pulse %02x to SoC", cmd); > hci_uart_set_flow_control(hu, true); > + ret = serdev_device_write(hu->serdev, &cmd, sizeof(cmd), 0); You're still using 0 as a timeout here which is broken, as I already told you. >>From 4.21 this will result in an indefinite timeout, but currently implies not to wait for a full write buffer to drain at all. As I also mentioned, you need to to make sure to call serdev_device_write_wakeup() in the write_wakup() path if you are going to use serdev_device_write() at all. Johan