diff mbox series

[v4,2/2] Bluetooth: hci_h5: Add power reset via gpio in h5_btrtl_open

Message ID 20220119061723.2862683-3-adeep@lexina.in (mailing list archive)
State Superseded
Headers show
Series Bluetooth: hci_h5: btrtl: Add support for RTL8822CS hci_ver 0x08 | expand

Checks

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tedd_an/checkpatch success Checkpatch PASS
tedd_an/gitlint success Gitlint PASS
tedd_an/subjectprefix success PASS

Commit Message

Viacheslav Jan. 19, 2022, 6:17 a.m. UTC
Add power reset via enable-gpios in h5_btrtl_open function.

Signed-off-by: Vyacheslav Bocharov <adeep@lexina.in>
---
 drivers/bluetooth/hci_h5.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Marcel Holtmann Jan. 19, 2022, 7:32 p.m. UTC | #1
Hi Vyacheslav,

> Add power reset via enable-gpios in h5_btrtl_open function.

this is too sparse commit message. Add explation and if possible also references on why that is needed.

Regards

Marcel
Viacheslav Jan. 20, 2022, 6:13 a.m. UTC | #2
Hi!

19.01.2022 22:32, Marcel Holtmann wrote:
> Hi Vyacheslav,
> 
>> Add power reset via enable-gpios in h5_btrtl_open function.
> 
> this is too sparse commit message. Add explation and if possible also references on why that is needed.

While testing the RTL8822CS SDIO WiFi/BT adapter, I found that in some 
cases the kernel could not initialize it. However, manually resetting 
the adapter via gpio allows it to start correctly.
Apparently at system start the adapter is in an undefined state 
(including the unknown state of gpio after starting uboot). A forced 
reset helps to initialize the adapter in most cases. Experimentally it 
was found that 100ms is enough to reset.

Since I am new to wireless drivers feel free correct me.
diff mbox series

Patch

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index 34286ffe0568..fdf504b0d265 100644
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -966,6 +966,11 @@  static void h5_btrtl_open(struct h5 *h5)
 		pm_runtime_enable(&h5->hu->serdev->dev);
 	}
 
+	/* The controller needs reset to startup */
+	gpiod_set_value_cansleep(h5->enable_gpio, 0);
+	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
+	msleep(100);
+
 	/* The controller needs up to 500ms to wakeup */
 	gpiod_set_value_cansleep(h5->enable_gpio, 1);
 	gpiod_set_value_cansleep(h5->device_wake_gpio, 1);