[PATCH v2 2/2] Bluetooth: btmtk: Do not discard the subsystem reset timeout

[Ismail Tarim <ismailtarim7@gmail.com>]

When the MTK_BT_RST_DONE poll times out, btmtk_usb_subsys_reset() logs
"Reset timeout" and keeps the error in err, but err is then overwritten
by the return value of the following btmtk_usb_id_get() call, so the
timeout is never reported to the caller.

Commit 25b6d7593a3a ("Bluetooth: btmtk: introduce btmtk reset work")
discarded the return value of the chip id read, so the function returned
the timeout error as intended. Commit 3dcb122b3064 ("Bluetooth: btusb:
mediatek: return error for failed reg access") started assigning err at
that call and silently dropped it.

Keep the timeout in a separate variable and return it, restoring the
original behaviour without changing the control flow.

Fixes: 3dcb122b3064 ("Bluetooth: btusb: mediatek: return error for failed reg access")
Signed-off-by: Ismail Tarim <ismailtarim7@gmail.com>
---
 drivers/bluetooth/btmtk.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
index dc702c0a6034..c0ed51567ed4 100644
--- a/drivers/bluetooth/btmtk.c
+++ b/drivers/bluetooth/btmtk.c
@@ -860,6 +860,7 @@ static u32 btmtk_usb_reset_done(struct hci_dev *hdev)
 
 int btmtk_usb_subsys_reset(struct hci_dev *hdev, u32 dev_id)
 {
+	int reset_err = 0;
 	u32 val;
 	int err;
 
@@ -958,8 +959,10 @@ int btmtk_usb_subsys_reset(struct hci_dev *hdev, u32 dev_id)
 
 	err = readx_poll_timeout(btmtk_usb_reset_done, hdev, val,
 				 val & MTK_BT_RST_DONE, 20000, 1000000);
-	if (err < 0)
+	if (err < 0) {
 		bt_dev_err(hdev, "Reset timeout");
+		reset_err = err;
+	}
 
 	if (dev_id == 0x7922) {
 		err = btmtk_usb_uhw_reg_write(hdev, MTK_UDMA_INT_STA_BT, 0x000000FF);
@@ -973,7 +976,7 @@ int btmtk_usb_subsys_reset(struct hci_dev *hdev, u32 dev_id)
 		return err ? err : -ENODEV;
 	}
 
-	return err;
+	return reset_err;
 }
 EXPORT_SYMBOL_GPL(btmtk_usb_subsys_reset);
 
-- 
2.55.0