[PATCH AUTOSEL 4.19 07/45] Bluetooth: btqca: Add a short delay before downloading the NVM

From: Sasha Levin
Date: Thu Aug 29 2019 - 14:26:01 EST

From: Matthias Kaehlcke <mka@xxxxxxxxxxxx>

[ Upstream commit 8059ba0bd0e4694e51c2ee6438a77b325f06c0d5 ]

On WCN3990 downloading the NVM sometimes fails with a "TLV response
size mismatch" error:

[ 174.949955] Bluetooth: btqca.c:qca_download_firmware() hci0: QCA Downloading qca/crnv21.bin
[ 174.958718] Bluetooth: btqca.c:qca_tlv_send_segment() hci0: QCA TLV response size mismatch

It seems the controller needs a short time after downloading the
firmware before it is ready for the NVM. A delay as short as 1 ms
seems sufficient, make it 10 ms just in case. No event is received
during the delay, hence we don't just silently drop an extra event.

Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/bluetooth/btqca.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
index ec9e03a6b7786..9e70f7c7e5659 100644
--- a/drivers/bluetooth/btqca.c
+++ b/drivers/bluetooth/btqca.c
@@ -363,6 +363,9 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
return err;

+ /* Give the controller some time to get ready to receive the NVM */
+ msleep(10);
/* Download NVM configuration */
config.type = TLV_TYPE_NVM;
if (soc_type == QCA_WCN3990)