On Thu, Jun 21, 2018 at 04:50:28PM +0530, Balakrishna Godavarthi wrote:
> Hi Matthias,
>
> On 2018-06-21 05:03, Matthias Kaehlcke wrote:
> > Hi Balakrishna,
> >
> > On Wed, Jun 20, 2018 at 04:23:25PM +0530, Balakrishna Godavarthi wrote:
> > > Hi Matthias,
> > >
> > > On 2018-06-20 01:33, Matthias Kaehlcke wrote:
> > > > On Tue, Jun 19, 2018 at 12:39:07PM +0530, Balakrishna Godavarthi wrote:
> > > > > Hi Matthias,
> > > > >
> > > > > Please find my comments inline.
> > > > >
> > > > > On 2018-06-19 02:49, Matthias Kaehlcke wrote:
> > > > > > On Sat, Jun 16, 2018 at 11:57:14AM +0530, Balakrishna Godavarthi wrote:
> > > > > >
> > > > > > > @@ -337,19 +337,20 @@ int qca_uart_setup(struct hci_dev *hdev,
> > > > > > > uint8_t baudrate)
> > > > > > >
> > > > > > > config.user_baud_rate = baudrate;
> > > > > > >
> > > > > > > - /* Get QCA version information */
> > > > > > > - err = qca_read_soc_version(hdev, &rome_ver);
> > > > > > > - if (err < 0 || rome_ver == 0) {
> > > > > > > - bt_dev_err(hdev, "QCA Failed to get version %d", err);
> > > > > > > - return err;
> > > > > > > + if (!soc_ver) {
> > > > > > > + /* Get QCA version information */
> > > > > > > + err = qca_read_soc_version(hdev, &soc_ver);
> > > > > > > + if (err < 0 || soc_ver == 0) {
> > > > > > > + bt_dev_err(hdev, "QCA Failed to get version %d", err);
> > > > > > > + return err;
> > > > > > > + }
> > > > > > > + bt_dev_info(hdev, "QCA controller version 0x%08x", soc_ver);
> > > > > > > }
> > > > > >
> > > > > > Why is this needed? A caller that passes in soc_ver = 0 could just
> > > > > > call qca_read_soc_version() themselves.
> > > > > [Bala]: hci_qca support two chip one ROME (already up-streamed) and
> > > > > other
> > > > > wcn3990.
> > > > > there setup sequence differs.
> > > > >
> > > > > wcn3900:
> > > > > 1. set baudrate to 115200
> > > > > 2. read soc version
> > > > > 3. set baudarte to 3.2Mbps
> > > > > 4. download firmware. (calls qca_uart_setup)
> > > > >
> > > > > ROME:
> > > > > 1. set baudrate to 3.0 mbps
> > > > > 2. calls qca_uart_setup to read soc version and download
> > > > > firmware.
> > > > >
> > > > > so to make use of existing function qca_setup_uart(). passing
> > > > > soc_ver
> > > > > as argument.
> > > > > if soc_ver is zero, then read soc version (i.e. for ROME chip).
> > > > >
> > > > > Pls let me know, if you have any queries.
> > > >
> > > > I don't really understand this argumentation. Let's look at the code
> > > > at the end of this series, where both Rome and wcn3900 are supported:
> > > >
> > > > https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1045608/6/drivers/bluetooth/hci_qca.c#1059
> > > >
> > > > The version could be read (for Rome only) after setting the operating
> > > > speed:
> > >
> > > [Bala]: yes we can read SoC version after setting operating baud
> > > rate. an
> > > advice from SoC vendor that, read SoC version before setting operating
> > > speed.
> > > one advantage from reading SoC version before setting
> > > operating
> > > baudrate,it will helps us to understand whether the soc is
> > > responding to any
> > > commands in default baud rate
> > > before setting operating speed.
> >
> > Is the recommendation for Rome or wcn3990? I was referring to Rome and
> > the current code sets the operating speed and then reads the SoC
> > version (inside qca_uart_setup())
> >
>
> [Bala]: my statement is wrt to wcn3990. yes, ROME will set operating speed
> and read version.
>
> > > > https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1045608/6/drivers/bluetooth/hci_qca.c#1111
> > > >
> > > > I concede that having two "if (qcadev->btsoc_type == XYZ)" branches in
> > > > qca_setup() is kinda ugly, but I think it's still better than the
> > > > conditional call of qca_read_soc_version() in qca_uart_setup().
> > >
> > > [Bala]: we require an if-else block for soc type.As wcn3900 support
> > > hardware flow control where as ROME is not supporting hardware flow
> > > control.
> >
> > Since you mention if-else and flow control I'm not sure if you
> > understood correctly what I suggested. My suggestion is to add
> > something like this:
> >
> > if (qcadev->btsoc_type == QCA_ROME) {
> > ret = qca_read_soc_version(hdev, &soc_ver);
> > if (ret < 0 || soc_ver == 0) {
> > // Note mka@: we might want to skip this log,
> > // qca_read_soc_version() already logs in all error paths
> > bt_dev_err(hdev, "Failed to get version %d", ret);
> > return ret;
> > }
> > }
> >
> > right here:
> >
> > https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1045608/6/drivers/bluetooth/hci_qca.c#1111
> >
> > which is functionally equivalent to the current code.
> >
> > You could even do the error check in the common code (just checking
> > for 'soc_ver == 0', assuming that qca_read_soc_version() doesn't set
> > it to something different in case of error).
> >
> > Anyway, I won't insist if you prefer it as is and Marcel is ok with it.
>
> [Bala]: thanks for clarifying my doubt, but if remove the
> qca_read_soc_version() from qca_uart_setup() and handle it qca_setup().
> in that case, we will have common blocks of code, when we integrate
> wcn3990 into existing qca_setup()
Excellent!
> static int qca_setup(struct hci_uart *hu)
> {
> ...
>
> qcadev = serdev_device_get_drvdata(hu->serdev);
>
> /* Patch downloading has to be done without IBS mode */
> clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
>
> /* Setup initial baudrate */
> speed = qca_get_speed(hu, QCA_INIT_SPEED);
> if (speed)
> qca_set_speed(hu, speed, QCA_INIT_SPEED);
I said earlier that a _set_speed() followed by a _get_speed() is a bit
odd, and that it would be better to get the speed first and pass it as
a parameter. After looking again over the larger code I'm not
convinced anymore this is such a good idea, since the above pattern is
repeated multiple times, when it could be just:
qca_set_speed(hu, QCA_INIT_SPEED)
(+ error handling, which is also missing in the code above)
Just a thought, not asking you to change it back, do whatever seems
best to you.
> if (qcadev->btsoc_type == QCA_WCN3990) {
> bt_dev_dbg(hdev, "setting up wcn3990");
> hci_uart_set_flow_control(hu, true);
> ret = qca_send_vendor_cmd(hdev, QCA_WCN3990_POWERON_PULSE);
> if (ret) {
> bt_dev_err(hdev, "failed to send power on command");
> return ret;
> }
>
> serdev_device_close(hu->serdev);
> ret = serdev_device_open(hu->serdev);
> if (ret) {
> bt_dev_err(hdev, "failed to open port");
> return ret;
> }
>
> msleep(100);
> speed = qca_get_speed(hu, QCA_INIT_SPEED);
> if (speed)
> qca_set_speed(hu, speed, QCA_INIT_SPEED);
>
> hci_uart_set_flow_control(hu, false);
> } else {
> bt_dev_info(hdev, "ROME setup");
> /* Setup user speed if needed */
> speed = qca_get_speed(hu, QCA_OPER_SPEED);
> if (speed) {
> ret = qca_set_speed(hu, speed, QCA_OPER_SPEED);
> if (ret)
> return ret;
>
> qca_baudrate = qca_get_baudrate_value(speed);
It seems setting 'qca_baudrate' could also be done in the common
path. Would require an extra qca_get_speed(hu, QCA_OPER_SPEED) call,
in exchange this would be done in a single place closer to where
'qca_baudrate' is actually used.
Actually as it is now 'qca_baudrate' could remain uninitialized for
Rome if no operating speed is defined, which judging from
qca_get_baudrate_value() should result in QCA_BAUDRATE_115200.
> }
> }
>
> ret = qca_read_soc_version(hdev, &soc_ver);
> if (ret < 0 || soc_ver == 0) {
> bt_dev_err(hdev, "Failed to get version %d", ret);
> return ret;
> }
> bt_dev_info(hdev, "wcn3990 controller version 0x%08x", soc_ver);
>
>
> if (qcadev->btsoc_type == QCA_WCN3990) {
> hci_uart_set_flow_control(hu, true);
> /* Setup user speed if needed */
> speed = qca_get_speed(hu, QCA_OPER_SPEED);
> if (speed) {
> ret = qca_set_speed(hu, speed, QCA_OPER_SPEED);
> if (ret)
> return ret;
>
> qca_baudrate = qca_get_baudrate_value(speed);
>
> }
>
> /* Setup patch / NVM configurations */
> ret = qca_uart_setup(hdev, qca_baudrate, qcadev->btsoc_type,
> soc_ver);
> if (!ret) {
> set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
> qca_debugfs_init(hdev);
> } else if (ret == -ENOENT) {
> /* No patch/nvm-config found, run with original fw/config */
> ret = 0;
> } else if (ret == -EAGAIN) {
> /*
> ...
> }
Overall looks good and should still become a bit more compact if the
handling of flow control is done in _set_speed() as you suggested in
"[PATCH v7 8/8] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth
chip wcn3990"
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