Il 13/09/22 00:18, sean.wang@xxxxxxxxxxxx ha scritto:
From: Sean Wang <sean.wang@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Hello Sean, thanks for the patch!
However, there's something to improve...
---
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 c3daba17de7f..4dc9cae3e937 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
..snip..
@@ -2910,18 +2918,14 @@ 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,
+ 100000, 1000000);
I agree with using readx_poll_timeout() instead of open coding the same, but
there's a catch: this macro uses usleep_range(), which is meant to be used
for sleeping less than ~20ms.
Even the kerneldoc at include/linux/iopoll.h advertises that:
* @sleep_us: Maximum time to sleep between reads in us (0
* tight-loops). Should be less than ~20ms since usleep_range
* is used (see Documentation/timers/timers-howto.rst).
So, if there's any reason for which you can't sleep for less than 100ms
per iteration, I'm afraid that you can't use readx_poll_timeout()...
...otherwise, please change sleep_us to 20000 and keep the timeout at 1 sec.
Regards,
Angelo
+ 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)
+ bt_dev_dbg(hdev, "Bluetooth Reset Successfully");
btusb_mtk_id_get(data, 0x70010200, &val);
if (!val)
