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SubjectRe: [PATCH v2 1/3] Bluetooth: btusb: mediatek: use readx_poll_timeout instead of open coding
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Il 30/09/22 02:23, sean.wang@mediatek.com ha scritto:
> From: Sean Wang <sean.wang@mediatek.com>
>
> Use readx_poll_timeout instead of open coding to poll the hardware reset
> status until it is done.
>
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> ---
> The patch is built and tested on the top of the patches
> [v6,1/3] Bluetooth: Add support for hci devcoredump
> [v6,2/3] Bluetooth: btusb: Add btusb devcoredump support
> [v6,3/3] Bluetooth: btintel: Add Intel devcoredump support
> which are contributed from Manish Mandlik
>
> v2: use 20ms as the unit to poll according to the requirement of
> readx_poll_timeout
> ---
> drivers/bluetooth/btusb.c | 32 ++++++++++++++++++--------------
> 1 file changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 4eb79e88f1d9..9ef0dc648573 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -2361,8 +2361,6 @@ static int btusb_send_frame_intel(struct hci_dev *hdev, struct sk_buff *skb)
> #define MTK_EP_RST_OPT 0x74011890
> #define MTK_EP_RST_IN_OUT_OPT 0x00010001
> #define MTK_BT_RST_DONE 0x00000100
> -#define MTK_BT_RESET_WAIT_MS 100
> -#define MTK_BT_RESET_NUM_TRIES 10
>
> static void btusb_mtk_wmt_recv(struct urb *urb)
> {
> @@ -2733,6 +2731,16 @@ static int btusb_mtk_id_get(struct btusb_data *data, u32 reg, u32 *id)
> return btusb_mtk_reg_read(data, reg, id);
> }
>
> +static u32 btusb_mtk_reset_done(struct hci_dev *hdev)

I'm sorry for not noticing that in v1, but...

...If you call this function "btusb_mtk_reset_done"...

> +{
> + struct btusb_data *data = hci_get_drvdata(hdev);
> + u32 val = 0;
> +
> + btusb_mtk_uhw_reg_read(data, MTK_BT_MISC, &val);
> +
> + return val;

...you shouldn't return the value of the entire MTK_BT_MISC register,
otherwise you should call this "btusb_mtk_read_bt_misc_reg".

I think that here, you should do

return val & MTK_BT_RST_DONE;

and then, for the readx_poll_timeout, you simply check if this function
returned 1, like:

err = readx_poll_timeout(btusb_mtk_reset_done, hdev, val, val,
20000, 1000000);

> +}
> +
> static int btusb_mtk_setup(struct hci_dev *hdev)
> {
> struct btusb_data *data = hci_get_drvdata(hdev);
> @@ -2922,7 +2930,7 @@ static void btusb_mtk_cmd_timeout(struct hci_dev *hdev)
> {
> struct btusb_data *data = hci_get_drvdata(hdev);
> u32 val;
> - int err, retry = 0;
> + int err;
>
> /* It's MediaTek specific bluetooth reset mechanism via USB */
> if (test_and_set_bit(BTUSB_HW_RESET_ACTIVE, &data->flags)) {
> @@ -2953,18 +2961,14 @@ static void btusb_mtk_cmd_timeout(struct hci_dev *hdev)
> btusb_mtk_uhw_reg_write(data, MTK_BT_SUBSYS_RST, 0);
> btusb_mtk_uhw_reg_read(data, MTK_BT_SUBSYS_RST, &val);
>
> - /* Poll the register until reset is completed */
> - do {
> - btusb_mtk_uhw_reg_read(data, MTK_BT_MISC, &val);
> - if (val & MTK_BT_RST_DONE) {
> - bt_dev_dbg(hdev, "Bluetooth Reset Successfully");
> - break;
> - }
> + err = readx_poll_timeout(btusb_mtk_reset_done, hdev, val,
> + val & MTK_BT_RST_DONE,
> + 20000, 1000000);
> + if (err < 0)
> + bt_dev_err(hdev, "Reset timeout");
>
> - bt_dev_dbg(hdev, "Polling Bluetooth Reset CR");
> - retry++;
> - msleep(MTK_BT_RESET_WAIT_MS);
> - } while (retry < MTK_BT_RESET_NUM_TRIES);
> + if (val & MTK_BT_RST_DONE)

You're already checking `if (err < 0)`, so this check is redundant.
If the polling didn't return a timeout, the register value contains
MTK_BT_RST_DONE for sure, so you can safely remove this check.

> + bt_dev_dbg(hdev, "Bluetooth Reset Successfully");
>

Regards,
Angelo


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