Re: [PATCH v1] Bluetooth: btusb: Add WCN6855 devcoredump support

From: Bjorn Andersson
Date: Fri Apr 07 2023 - 12:10:19 EST


On Fri, Apr 07, 2023 at 11:29:36AM +0800, Tim Jiang wrote:
> WCN6855 will report memdump via ACL data or HCI event when
> it get crashed, so we collect memdump to debug firmware.
>
> Signed-off-by: Tim Jiang <quic_tjiang@xxxxxxxxxxx>
> ---
> drivers/bluetooth/btusb.c | 221 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 221 insertions(+)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 2303b0a66323..ecc346d8b2ea 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -752,6 +752,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
> #define BTUSB_WAKEUP_AUTOSUSPEND 14
> #define BTUSB_USE_ALT3_FOR_WBS 15
> #define BTUSB_ALT6_CONTINUOUS_TX 16
> +#define BTUSB_HW_SSR_ACTIVE 17
>
> struct btusb_data {
> struct hci_dev *hdev;
> @@ -904,6 +905,11 @@ static void btusb_qca_cmd_timeout(struct hci_dev *hdev)
> struct btusb_data *data = hci_get_drvdata(hdev);
> struct gpio_desc *reset_gpio = data->reset_gpio;
>
> + if (test_bit(BTUSB_HW_SSR_ACTIVE, &data->flags)) {
> + bt_dev_info(hdev, "Defer cmd_timeout due to dump active");

"Ramdump in progress, defer cmd_timeout"

> + return;
> + }
> +
> if (++data->cmd_timeout_cnt < 5)
> return;
>
> @@ -3294,6 +3300,213 @@ static int btusb_set_bdaddr_wcn6855(struct hci_dev *hdev,
> return 0;
> }
>
> +#define QCA_MEMDUMP_ACL_HANDLE 0x2EDD
> +#define QCA_MEMDUMP_SIZE_MAX 0x100000
> +#define QCA_MEMDUMP_VSE_CLASS 0x01
> +#define QCA_MEMDUMP_MSG_TYPE 0x08
> +struct qca_dump_hdr {
> + u8 vse_class;
> + u8 msg_type;
> + __le16 seqno;
> + u8 reserved;
> + union {
> + u8 data[0];
> + struct {
> + __le32 ram_dump_size;
> + u8 data0[0];
> + } __packed;
> + };
> +} __packed;
> +
> +struct qca_dump_info {
> + /* fields for dump collection */
> + u16 id_vendor;
> + u16 id_product;
> + u32 fw_version;
> + u32 controller_id;
> + u32 ram_dump_size;
> + u32 ram_dump_offs;
> + u16 ram_dump_seqno;
> +};
> +
> +static struct qca_dump_info qca_dump = {0};

Do you really need to keep track of this across the individual packets?

What if I connect two btqca devices to my machine?

> +
> +static void btusb_dump_hdr_qca(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + char buf[128];
> +
> + snprintf(buf, sizeof(buf), "Controller Name: 0x%x\n",
> + qca_dump.controller_id);
> + skb_put_data(skb, buf, strlen(buf));
> +
> + snprintf(buf, sizeof(buf), "Firmware Version: 0x%x\n",
> + qca_dump.fw_version);
> + skb_put_data(skb, buf, strlen(buf));
> +
> + snprintf(buf, sizeof(buf), "Driver: %s\nVendor: qca\n",
> + btusb_driver.name);
> + skb_put_data(skb, buf, strlen(buf));
> +
> + snprintf(buf, sizeof(buf), "VID: 0x%x\nPID:0x%x\n",
> + qca_dump.id_vendor, qca_dump.id_product);
> + skb_put_data(skb, buf, strlen(buf));
> +
> + snprintf(buf, sizeof(buf), "Lmp Subversion: 0x%x\n",
> + hdev->lmp_subver);
> + skb_put_data(skb, buf, strlen(buf));
> +}
> +
> +static void btusb_coredump_qca(struct hci_dev *hdev)
> +{
> + static const u8 param[] = { 0x26 };
> + struct sk_buff *skb;
> +
> + skb = __hci_cmd_sync(hdev, 0xfc0c, 1, param, HCI_CMD_TIMEOUT);
> + if (IS_ERR(skb))
> + bt_dev_err(hdev, "%s: triggle crash failed (%ld)", __func__, PTR_ERR(skb));
> + kfree_skb(skb);
> +}
> +
> +/*
> + * ==0: not a dump pkt.
> + * < 0: fails to handle a dump pkt
> + * > 0: otherwise.
> + */
> +static int handle_dump_pkt_qca(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + int ret = 0;
> + u8 pkt_type;
> + u8 *sk_ptr;
> + unsigned int sk_len;
> + u16 seqno;
> + u32 ram_dump_size;
> +
> + struct hci_event_hdr *event_hdr;
> + struct hci_acl_hdr *acl_hdr;
> + struct qca_dump_hdr *dump_hdr;
> + struct btusb_data *btdata = hci_get_drvdata(hdev);
> + struct usb_device *udev = btdata->udev;
> +
> + pkt_type = hci_skb_pkt_type(skb);
> + sk_ptr = skb->data;
> + sk_len = skb->len;
> +
> + if (pkt_type == HCI_ACLDATA_PKT) {
> + acl_hdr = hci_acl_hdr(skb);
> + if (le16_to_cpu(acl_hdr->handle) != QCA_MEMDUMP_ACL_HANDLE)
> + return 0;
> + sk_ptr += HCI_ACL_HDR_SIZE;
> + sk_len -= HCI_ACL_HDR_SIZE;
> + event_hdr = (struct hci_event_hdr *)sk_ptr;
> + } else {
> + event_hdr = hci_event_hdr(skb);
> + }
> +
> + if (event_hdr->evt != HCI_VENDOR_PKT)
> + return 0;
> + if (event_hdr->plen != (sk_len - HCI_EVENT_HDR_SIZE))
> + return 0;
> + sk_ptr += HCI_EVENT_HDR_SIZE;
> + sk_len -= HCI_EVENT_HDR_SIZE;
> +
> + if (sk_len < offsetof(struct qca_dump_hdr, data))
> + return 0;
> + dump_hdr = (struct qca_dump_hdr *)sk_ptr;
> + if ((dump_hdr->vse_class != QCA_MEMDUMP_VSE_CLASS)
> + || (dump_hdr->msg_type != QCA_MEMDUMP_MSG_TYPE))
> + return 0;
> +
> + /*it is dump pkt now*/
> + ret = 1;

Perhaps you can redesign this so that you don't need to set ret = 1 in
multiple places?

> + seqno = le16_to_cpu(dump_hdr->seqno);
> + if (seqno == 0) {
> + set_bit(BTUSB_HW_SSR_ACTIVE, &btdata->flags);
> + ram_dump_size = le32_to_cpu(dump_hdr->ram_dump_size);
> + if (!ram_dump_size || (ram_dump_size > QCA_MEMDUMP_SIZE_MAX)) {
> + ret = -EILSEQ;
> + bt_dev_err(hdev, "Invalid memdump size(%u)",
> + ram_dump_size);
> + goto out;
> + }
> +
> + ret = hci_devcd_init(hdev, ram_dump_size);
> + if (ret < 0) {
> + bt_dev_err(hdev, "memdump init error(%d)", ret);
> + goto out;
> + }
> + ret = 1;
> +
> + qca_dump.ram_dump_size = ram_dump_size;
> + qca_dump.ram_dump_offs = 0;
> + qca_dump.ram_dump_seqno = 0;
> + sk_ptr += offsetof(struct qca_dump_hdr, data0);
> + sk_len -= offsetof(struct qca_dump_hdr, data0);
> +
> + usb_disable_autosuspend(udev);
> + bt_dev_info(hdev, "%s memdump size(%u)\n",
> + (pkt_type == HCI_ACLDATA_PKT) ? "ACL" : "event",
> + ram_dump_size);
> + } else {
> + sk_ptr += offsetof(struct qca_dump_hdr, data);
> + sk_len -= offsetof(struct qca_dump_hdr, data);
> + }
> +
> + if (!qca_dump.ram_dump_size) {
> + ret = -EINVAL;
> + bt_dev_err(hdev, "memdump is not active");
> + goto out;
> + }
> +
> + if ((seqno != qca_dump.ram_dump_seqno) && (seqno != 0xFFFF)) {
> + ret = -EILSEQ;
> + bt_dev_err(hdev,
> + "expected memdump seqno(%u) is not received(%u)\n",
> + qca_dump.ram_dump_seqno, seqno);
> + hci_devcd_abort(hdev);
> + goto out;
> + }
> +
> + skb_pull(skb, skb->len - sk_len);
> + hci_devcd_append(hdev, skb);
> + qca_dump.ram_dump_offs += sk_len;
> + qca_dump.ram_dump_seqno++;
> + if (seqno != 0xFFFF)
> + return ret;

It wasn't immediately clear to me that this means "return OK, but we're
waiting for more data".

How about turning this the other way around?

if (all_data_received) {
bt_dev_info("memdump done");
hci_devcd_complete();
...
}

...

> + hci_devcd_complete(hdev);
> +
> +out:
> + if (qca_dump.ram_dump_size) {

So if I get seqno == 0, followed by seqno == 2 we will print memdump
Done and return -EILSEQ?

Regards,
Bjorn

> + usb_enable_autosuspend(udev);
> + bt_dev_info(hdev,
> + "memdump Done: pkts(%u), dumped(%u)/total(%u)\n",
> + qca_dump.ram_dump_seqno, qca_dump.ram_dump_offs,
> + qca_dump.ram_dump_size);
> + }
> + qca_dump.ram_dump_size = 0;
> + qca_dump.ram_dump_offs = 0;
> + qca_dump.ram_dump_seqno = 0;
> + clear_bit(BTUSB_HW_SSR_ACTIVE, &btdata->flags);
> +
> + if (ret < 0)
> + kfree_skb(skb);
> + return ret;
> +}
> +
> +static int btusb_recv_acl_qca(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + if (handle_dump_pkt_qca(hdev, skb))
> + return 0;
> + return hci_recv_frame(hdev, skb);
> +}
> +
> +static int btusb_recv_evt_qca(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + if (handle_dump_pkt_qca(hdev, skb))
> + return 0;
> + return hci_recv_frame(hdev, skb);
> +}
> +
> +
> #define QCA_DFU_PACKET_LEN 4096
>
> #define QCA_GET_TARGET_VERSION 0x09
> @@ -3628,6 +3841,9 @@ static int btusb_setup_qca(struct hci_dev *hdev)
> if (err < 0)
> return err;
>
> + qca_dump.fw_version = le32_to_cpu(ver.patch_version);
> + qca_dump.controller_id = le32_to_cpu(ver.rom_version);
> +
> if (!(status & QCA_SYSCFG_UPDATED)) {
> err = btusb_setup_qca_load_nvm(hdev, &ver, info);
> if (err < 0)
> @@ -4117,6 +4333,11 @@ static int btusb_probe(struct usb_interface *intf,
> }
>
> if (id->driver_info & BTUSB_QCA_WCN6855) {
> + qca_dump.id_vendor = id->idVendor;
> + qca_dump.id_product = id->idProduct;
> + data->recv_event = btusb_recv_evt_qca;
> + data->recv_acl = btusb_recv_acl_qca;
> + hci_devcd_register(hdev, btusb_coredump_qca, btusb_dump_hdr_qca, NULL);
> data->setup_on_usb = btusb_setup_qca;
> hdev->shutdown = btusb_shutdown_qca;
> hdev->set_bdaddr = btusb_set_bdaddr_wcn6855;
> --
> 2.17.1
>