[PATCH v9] Bluetooth: btqca: inject command complete event during fw download

[Matthias Kaehlcke]

From: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>

Latest qualcomm chips are not sending an command complete event for
every firmware packet sent to chip. They only respond with a vendor
specific event for the last firmware packet. This optimization will
decrease the BT ON time. Due to this we are seeing a timeout error
message logs on the console during firmware download. Now we are
injecting a command complete event once we receive an vendor specific
event for the last RAM firmware packet.

Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
Tested-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
Changes in v9:
- define QCA_HCI_CC_SUCCESS (again)
- use QCA_HCI_CC_OPCODE instead of HCI_OP_NOP

Changes in v8:
- renamed QCA_HCI_CC_SUCCESS to QCA_HCI_CC_OPCODE
- use 0xFC00 as opcode of the injected event instead of 0
- added Matthias' tags from the v7 review
---
 drivers/bluetooth/btqca.c | 39 ++++++++++++++++++++++++++++++++++++++-
 drivers/bluetooth/btqca.h |  4 ++++
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
index cc12eecd9e4d..711ce526e03c 100644
--- a/drivers/bluetooth/btqca.c
+++ b/drivers/bluetooth/btqca.c
@@ -144,6 +144,7 @@ static void qca_tlv_check_data(struct rome_config *config,
 		 * In case VSE is skipped, only the last segment is acked.
 		 */
 		config->dnld_mode = tlv_patch->download_mode;
+		config->dnld_type = config->dnld_mode;
 
 		BT_DBG("Total Length           : %d bytes",
 		       le32_to_cpu(tlv_patch->total_size));
@@ -264,6 +265,31 @@ static int qca_tlv_send_segment(struct hci_dev *hdev, int seg_size,
 	return err;
 }
 
+static int qca_inject_cmd_complete_event(struct hci_dev *hdev)
+{
+	struct hci_event_hdr *hdr;
+	struct hci_ev_cmd_complete *evt;
+	struct sk_buff *skb;
+
+	skb = bt_skb_alloc(sizeof(*hdr) + sizeof(*evt) + 1, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = skb_put(skb, sizeof(*hdr));
+	hdr->evt = HCI_EV_CMD_COMPLETE;
+	hdr->plen = sizeof(*evt) + 1;
+
+	evt = skb_put(skb, sizeof(*evt));
+	evt->ncmd = 1;
+	evt->opcode = QCA_HCI_CC_OPCODE;
+
+	skb_put_u8(skb, QCA_HCI_CC_SUCCESS);
+
+	hci_skb_pkt_type(skb) = HCI_EVENT_PKT;
+
+	return hci_recv_frame(hdev, skb);
+}
+
 static int qca_download_firmware(struct hci_dev *hdev,
 				  struct rome_config *config)
 {
@@ -297,11 +323,22 @@ static int qca_download_firmware(struct hci_dev *hdev,
 		ret = qca_tlv_send_segment(hdev, segsize, segment,
 					    config->dnld_mode);
 		if (ret)
-			break;
+			goto out;
 
 		segment += segsize;
 	}
 
+	/* Latest qualcomm chipsets are not sending a command complete event
+	 * for every fw packet sent. They only respond with a vendor specific
+	 * event for the last packet. This optimization in the chip will
+	 * decrease the BT in initialization time. Here we will inject a command
+	 * complete event to avoid a command timeout error message.
+	 */
+	if ((config->dnld_type == ROME_SKIP_EVT_VSE_CC ||
+	    config->dnld_type == ROME_SKIP_EVT_VSE))
+		return qca_inject_cmd_complete_event(hdev);
+
+out:
 	release_firmware(fw);
 
 	return ret;
diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h
index 4c4fe2b5b7b7..718de9608ff1 100644
--- a/drivers/bluetooth/btqca.h
+++ b/drivers/bluetooth/btqca.h
@@ -41,6 +41,9 @@
 #define QCA_WCN3990_POWERON_PULSE	0xFC
 #define QCA_WCN3990_POWEROFF_PULSE	0xC0
 
+#define QCA_HCI_CC_OPCODE		0xFC00
+#define QCA_HCI_CC_SUCCESS		0x00
+
 enum qca_baudrate {
 	QCA_BAUDRATE_115200 	= 0,
 	QCA_BAUDRATE_57600,
@@ -82,6 +85,7 @@ struct rome_config {
 	char fwname[64];
 	uint8_t user_baud_rate;
 	enum rome_tlv_dnld_mode dnld_mode;
+	enum rome_tlv_dnld_mode dnld_type;
 };
 
 struct edl_event_hdr {
-- 
2.22.0.rc1.257.g3120a18244-goog