在 2019-03-07 14:49，Balakrishna Godavarthi 写道：
Hi Stepen,
On 2019-03-07 04:03, Stephen Boyd wrote:
Quoting Balakrishna Godavarthi (2019-03-06 08:21:13)
This patch enables enough time to ROME controller to bootup
after we bring the enable ping out of reset.
Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
---
Any Fixes tag? And maybe some more explanation or background on where
150 ms sleep comes from would be useful. Was it determined
experimentally or did it come from a datasheet somewhere? Does the
time
differ between boards?
[Bala]: this was observed in our stress testing and even the CHIP
firmware team
confirmed that BT chip required at least 150 ms to boot up.
@Rocky to confirm my statement.
drivers/bluetooth/hci_qca.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/bluetooth/hci_qca.c
b/drivers/bluetooth/hci_qca.c
index 237aea34b69f..1953b13511e7 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -508,6 +508,8 @@ static int qca_open(struct hci_uart *hu)
qcadev = serdev_device_get_drvdata(hu->serdev);
if (qcadev->btsoc_type != QCA_WCN3990) {
gpiod_set_value_cansleep(qcadev->bt_en, 1);
+ /* Controller needs time to bootup. */
+ msleep(150);
} else {
hu->init_speed = qcadev->init_speed;
hu->oper_speed = qcadev->oper_speed;
Yes,ROME firmware needs 150ms to boot up after toggle the BT_EN pin.
