From: Balakrishna Godavarthi <bgodavar@codeaurora.org>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: marcel@holtmann.org, johan.hedberg@gmail.com,
linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH v1 2/4] Bluetooth: hci_qca: Pull RTS line high for baudrate change command
Date: Wed, 14 Nov 2018 12:02:16 +0530 [thread overview]
Message-ID: <25c29e35b32ca71fe6d0b02f4d6ed559@codeaurora.org> (raw)
In-Reply-To: <20181114015504.GH22824@google.com>
Hi Matthias,
On 2018-11-14 07:25, Matthias Kaehlcke wrote:
> On Tue, Nov 06, 2018 at 05:35:26PM +0530, Balakrishna Godavarthi wrote:
>> This patch will pull the RTS line high instead of turning off the
>> flow control, while changing baudrate of host and chip.
>
> Please don't only describe what is changed, but also why this change
> is necessary.
>
> IIUC the BT chip honors flow control during baudrate changes, however
> it sometimes sends 'garbage' which results in "Bluetooth: hci0: Frame
> reassembly failed (-84)" messages.
>
[Bala]: will update the commit text.
>> Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
>> ---
>> drivers/bluetooth/hci_qca.c | 23 ++++++++++++-----------
>> 1 file changed, 12 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>> index 051f081d1835..8301663f0004 100644
>> --- a/drivers/bluetooth/hci_qca.c
>> +++ b/drivers/bluetooth/hci_qca.c
>> @@ -963,7 +963,6 @@ static int qca_set_baudrate(struct hci_dev *hdev,
>> uint8_t baudrate)
>> struct hci_uart *hu = hci_get_drvdata(hdev);
>> struct qca_data *qca = hu->priv;
>> struct sk_buff *skb;
>> - struct qca_serdev *qcadev;
>> u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 };
>>
>> if (baudrate > QCA_BAUDRATE_3200000)
>> @@ -977,13 +976,6 @@ static int qca_set_baudrate(struct hci_dev *hdev,
>> uint8_t baudrate)
>> return -ENOMEM;
>> }
>>
>> - /* Disabling hardware flow control is mandatory while
>> - * sending change baudrate request to wcn3990 SoC.
>> - */
>> - qcadev = serdev_device_get_drvdata(hu->serdev);
>> - if (qcadev->btsoc_type == QCA_WCN3990)
>> - hci_uart_set_flow_control(hu, true);
>> -
>> /* Assign commands to change baudrate and packet type. */
>> skb_put_data(skb, cmd, sizeof(cmd));
>> hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
>> @@ -999,9 +991,6 @@ static int qca_set_baudrate(struct hci_dev *hdev,
>> uint8_t baudrate)
>> schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
>> set_current_state(TASK_RUNNING);
>>
>> - if (qcadev->btsoc_type == QCA_WCN3990)
>> - hci_uart_set_flow_control(hu, false);
>> -
>> return 0;
>> }
>>
>> @@ -1086,6 +1075,7 @@ static int qca_check_speeds(struct hci_uart *hu)
>> static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type
>> speed_type)
>> {
>> unsigned int speed, qca_baudrate;
>> + struct qca_serdev *qcadev;
>> int ret;
>>
>> if (speed_type == QCA_INIT_SPEED) {
>> @@ -1097,6 +1087,14 @@ static int qca_set_speed(struct hci_uart *hu,
>> enum qca_speed_type speed_type)
>> if (!speed)
>> return 0;
>>
>> + /* Pulling RTS line to high is mandatory while sending change
>> + * baudrate request to SoC and also while setting the host
>> + * baudrate.
>> + */
>
> Instead of just stating that this is 'mandatory' explain why it is
> needed. Also better say 'Deassert RTS' instead of the more lower level
> 'Pulling RTS line to high'. It could be something like 'Deassert RTS
> to prevent the BT controller from sending garbage during the baudrate
> change.'
>
[Bala]: will update the comment.
>> + qcadev = serdev_device_get_drvdata(hu->serdev);
>> + if (qcadev->btsoc_type == QCA_WCN3990)
>> + serdev_device_set_rts(hu->serdev, false);
>> +
>> qca_baudrate = qca_get_baudrate_value(speed);
>> bt_dev_dbg(hu->hdev, "Set UART speed to %d", speed);
>> ret = qca_set_baudrate(hu->hdev, qca_baudrate);
>> @@ -1104,6 +1102,9 @@ static int qca_set_speed(struct hci_uart *hu,
>> enum qca_speed_type speed_type)
>> return ret;
>>
>> host_set_baudrate(hu, speed);
>> +
>> + if (qcadev->btsoc_type == QCA_WCN3990)
>> + serdev_device_set_rts(hu->serdev, true);
>> }
>>
>> return 0;
>
> Tested-by: Matthias Kaehlcke <mka@chromium.org>
Thanks for testing.
--
Regards
Balakrishna.
next prev parent reply other threads:[~2018-11-14 6:32 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-06 12:05 Bug fixes for Qualcomm BT chip wcn3990 Balakrishna Godavarthi
2018-11-06 12:05 ` [PATCH v1 1/4] Bluetooth: hci_qca: use wait_until_sent() for power pulses Balakrishna Godavarthi
2018-11-14 0:17 ` Matthias Kaehlcke
2018-11-14 6:29 ` Balakrishna Godavarthi
2018-11-14 15:27 ` Johan Hovold
2018-11-15 14:34 ` Balakrishna Godavarthi
2018-11-16 9:47 ` Johan Hovold
2018-11-06 12:05 ` [PATCH v1 2/4] Bluetooth: hci_qca: Pull RTS line high for baudrate change command Balakrishna Godavarthi
2018-11-14 1:55 ` Matthias Kaehlcke
2018-11-14 6:32 ` Balakrishna Godavarthi [this message]
2018-11-06 12:05 ` [PATCH v1 3/4] Bluetooth: hci_qca: clear HCI_QUIRK_RESET_ON_CLOSE flag Balakrishna Godavarthi
2018-11-06 12:33 ` Marcel Holtmann
2018-11-06 12:44 ` Balakrishna Godavarthi
2018-11-06 13:02 ` Marcel Holtmann
2018-11-06 13:14 ` Balakrishna Godavarthi
2018-11-06 13:36 ` Balakrishna Godavarthi
2018-11-14 7:48 ` Marcel Holtmann
2018-11-14 13:37 ` Balakrishna Godavarthi
2018-11-14 2:14 ` Matthias Kaehlcke
2018-11-14 6:50 ` Balakrishna Godavarthi
2018-11-06 12:05 ` [PATCH v1 4/4] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990 Balakrishna Godavarthi
2018-11-14 19:36 ` Matthias Kaehlcke
2018-11-15 11:40 ` Balakrishna Godavarthi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=25c29e35b32ca71fe6d0b02f4d6ed559@codeaurora.org \
--to=bgodavar@codeaurora.org \
--cc=hemantg@codeaurora.org \
--cc=johan.hedberg@gmail.com \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-bluetooth@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marcel@holtmann.org \
--cc=mka@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).