Re: [PATCH v1 1/3] Bluetooth: btintel_pcie: Add initial YoYo debug support

[Luiz Augusto von Dentz]

Hi Ajay,

On Tue, Oct 13, 2026 at 2:26 PM Ajay KV <ajay.k.v@xxxxxxxxx> wrote:
>
> From: Ajaykv <ajay.k.v@xxxxxxxxx>
>
> Add an optional YoYo firmware configuration path to the Intel PCIe
> Bluetooth driver. Read DBG_PATH and ENABLE_INI from
> ibt_bt_dbg_cfg.ini, and load intel/ibt_debug_yoyo.bin only when YoYo
> is enabled and host DRAM routing is selected.
>
> Introduce a runtime context and bounded TLV-stream validation helper.
> Initialize and clean up the context with PCI probe and removal, while
> falling back to legacy debug behavior if optional YoYo data is missing
> or invalid.
>
> Runtime validation of the complete P1-P3 series produced:
> [    3.286504] Bluetooth: Core ver 2.22
> [    3.297359] Bluetooth: HCI device and connection manager initialized
> [    3.297373] Bluetooth: HCI socket layer initialized
> [    3.297376] Bluetooth: L2CAP socket layer initialized
> [    3.297384] Bluetooth: SCO socket layer initialized
> [    3.332848] Bluetooth: YoYo: configuration loaded and validated
> [3.360857-3.361712] Bluetooth: DBGC1-3: each 16 x 256 KiB (4 MiB)
> [3.361715] Bluetooth: MDBGC DBGC1-3: each 16 x 256 KiB
> [    3.397439] Bluetooth: hci0: Device revision is 0
> [    3.397442] Bluetooth: hci0: Secure boot is enabled
> [    3.397443] Bluetooth: hci0: OTP lock is disabled
> [    3.397444] Bluetooth: hci0: API lock is enabled
> [    3.397444] Bluetooth: hci0: Debug lock is disabled
>
> Signed-off-by: Ajaykv <ajay.k.v@xxxxxxxxx>
>
> diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
> index d5eb2568af2e..7d933755b291 100644
> --- a/drivers/bluetooth/Makefile
> +++ b/drivers/bluetooth/Makefile
> @@ -14,7 +14,7 @@ obj-$(CONFIG_BT_HCIBTUSB)     += btusb.o
>  obj-$(CONFIG_BT_HCIBTSDIO)     += btsdio.o
>
>  obj-$(CONFIG_BT_INTEL)         += btintel.o
> -obj-$(CONFIG_BT_INTEL_PCIE)    += btintel_pcie.o btintel.o
> +obj-$(CONFIG_BT_INTEL_PCIE)    += btintel_pcie.o btintel.o btintel_pcie_debug.o
>  obj-$(CONFIG_BT_ATH3K)         += ath3k.o
>  obj-$(CONFIG_BT_MRVL)          += btmrvl.o
>  obj-$(CONFIG_BT_MRVL_SDIO)     += btmrvl_sdio.o
> diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
> index 3a555aa50c87..e28f527d6d29 100644
> --- a/drivers/bluetooth/btintel_pcie.c
> +++ b/drivers/bluetooth/btintel_pcie.c
> @@ -203,6 +203,103 @@ static inline bool btintel_pcie_dbg_to_wifi(struct btintel_pcie_data *data)
>         return data->dbg_path_cache != BTINTEL_PCIE_DRAM;
>  }
>
> +/* Name of the optional INI file used to override the default dbg_path
> + * (data->dbg_path_cache) and yoyo ini settings.
> + */
> +#define BTINTEL_PCIE_DBG_INI_FILE "ibt_bt_dbg_cfg.ini"
> +
> +/* Loads optional "DBG_PATH=<value>" and ENABLE_INI=<value>
> + * overrides from BTINTEL_PCIE_DBG_INI_FILE
> + * and applies them to data->dbg_path_cache and data->enable_ini.
> + *
> + * DBG_PATH accepts BTINTEL_PCIE_WIFI_DBGC (0x06, default) and
> + * BTINTEL_PCIE_DRAM (0x01, legacy); an invalid or missing entry leaves
> + * the cached value set by the caller unchanged.
> + *
> + * ENABLE_INI accepts 1 (enabled) or 0 (disabled); an invalid or missing
> + * entry leaves data->enable_ini unchanged.
> + */
> +static void btintel_pcie_load_dbg_path_from_ini(struct btintel_pcie_data *data)
> +{
> +       const struct firmware *fw;
> +       const char *ini_file = BTINTEL_PCIE_DBG_INI_FILE;
> +       char *buf, *cursor, *line;
> +       bool dbg_path_applied = false;
> +       int err;
> +
> +       err = request_firmware_direct(&fw, ini_file, &data->pdev->dev);
> +       if (err < 0) {
> +               BT_ERR("%s not found (%d), using dbg_path=0x%02x ",
> +                      ini_file, err, data->dbg_path_cache);
> +               return;
> +       }
> +
> +       buf = kmemdup_nul(fw->data, fw->size, GFP_KERNEL);
> +       release_firmware(fw);
> +       if (!buf)
> +               return;
> +
> +       cursor = buf;
> +       while ((line = strsep(&cursor, "\n"))) {
> +               char *eq;
> +               char *val;
> +               uint parsed;
> +
> +               line = strim(line);
> +               if (!line[0] || line[0] == '#' || line[0] == ';')
> +                       continue;
> +
> +               eq = strchr(line, '=');
> +               if (!eq)
> +                       continue;
> +
> +               *eq = '\0';
> +               line = strim(line);
> +               val = strim(eq + 1);
> +
> +               /* Accept "DBG_PATH"/"dbg_path"
> +                * case-insensitively as the key.
> +                */
> +               if (!strcasecmp(line, "DBG_PATH")) {
> +                       BT_INFO("Read DBG_PATH from %s: '%s'", ini_file, val);
> +
> +                       /* base 0 lets kstrtouint accept "0x06", "6", etc. */
> +                       if (kstrtouint(val, 0, &parsed) == 0 &&
> +                           (parsed == BTINTEL_PCIE_DRAM ||
> +                            parsed == BTINTEL_PCIE_WIFI_DBGC)) {
> +                               data->dbg_path_cache = parsed;
> +                               dbg_path_applied = true;
> +                               BT_INFO("WRT dbg_path accepted: 0x%02x",
> +                                       data->dbg_path_cache);
> +                       } else {
> +                               BT_ERR("Invalid DBG_PATH='%s' in %s, using dbg_path=0x%02x",
> +                                      val, ini_file, data->dbg_path_cache);
> +                       }
> +               } else if (!strcasecmp(line, "ENABLE_INI")) {
> +                       BT_INFO("Read ENABLE_INI from %s: '%s'", ini_file, val);
> +
> +                       if (kstrtouint(val, 0, &parsed) == 0 &&
> +                           (parsed == 0 || parsed == 1)) {
> +                               data->enable_ini = !!parsed;
> +                               BT_INFO("WRT enable_ini accepted: %u",
> +                                       data->enable_ini);
> +                       } else {
> +                               BT_ERR("Invalid ENABLE_INI='%s' in %s, using enable_ini=%u",
> +                                      val, ini_file, data->enable_ini);
> +                       }
> +               }
> +       }
> +
> +       if (dbg_path_applied)
> +               BT_DBG("Loaded dbg_path=0x%02x from %s", data->dbg_path_cache, ini_file);
> +       else
> +               BT_ERR("No valid DBG_PATH in %s, dbg_path=0x%02x", ini_file, data->dbg_path_cache);
> +
> +       BT_DBG("ENABLE_INI effective state: %u", data->enable_ini);
> +
> +       kfree(buf);
> +}
> +
>  /* Helper function to allocate and setup a debug buffer group
>   * @data: driver data structure
>   * @buf: pointer to data_buf array pointer
> @@ -4097,10 +4194,25 @@ static int btintel_pcie_probe(struct pci_dev *pdev,
>         data->boot_stage_cache = 0x00;
>         data->img_resp_cache = 0x00;
>         data->dbg_path_cache = BTINTEL_PCIE_WIFI_DBGC;
> +       data->enable_ini = false;
> +       btintel_pcie_yoyo_init(&data->yoyo);
>         /* FLR can be invoked by echoing to debugfs path, so explicitly
>          * initialized
>          */
>         data->reset_type = BTINTEL_PCIE_IOSF_PRR_FLR;
> +
> +       btintel_pcie_load_dbg_path_from_ini(data);
> +       if (data->dbg_path_cache != BTINTEL_PCIE_DRAM)
> +               data->enable_ini = false;
> +
> +       if (data->enable_ini) {
> +               err = btintel_pcie_yoyo_load_and_parse(&data->yoyo, &pdev->dev);
> +               if (err) {
> +                       BT_WARN("YoYo is not configured (%d)", err);
> +                       btintel_pcie_yoyo_cleanup(&data->yoyo);
> +               }
> +       }
> +
>         err = btintel_pcie_config_pcie(pdev, data);
>         if (err)
>                 goto exit_error;
> @@ -4128,11 +4240,14 @@ static int btintel_pcie_probe(struct pci_dev *pdev,
>         if (err)
>                 goto exit_error;
>
> +       data->yoyo.hdev = data->hdev;
>         bt_dev_dbg(data->hdev, "cnvi: 0x%8.8x cnvr: 0x%8.8x", data->cnvi,
>                    data->cnvr);
>         return 0;
>
>  exit_error:
> +       btintel_pcie_yoyo_cleanup(&data->yoyo);
> +
>         /* reset device before exit */
>         btintel_pcie_reset_bt(data);
>
> @@ -4173,6 +4288,8 @@ static void btintel_pcie_remove(struct pci_dev *pdev)
>         if (current_work() != &data->reset_work)
>                 disable_work_sync(&data->reset_work);
>
> +       btintel_pcie_yoyo_cleanup(&data->yoyo);
> +
>         btintel_pcie_disable_interrupts(data);
>
>         btintel_pcie_synchronize_irqs(data);
> diff --git a/drivers/bluetooth/btintel_pcie.h b/drivers/bluetooth/btintel_pcie.h
> index 3030b4e8b750..0a4e508d0beb 100644
> --- a/drivers/bluetooth/btintel_pcie.h
> +++ b/drivers/bluetooth/btintel_pcie.h
> @@ -6,6 +6,8 @@
>   *  Copyright (C) 2024  Intel Corporation
>   */
>
> +#include "btintel_pcie_debug.h"
> +
>  /* Control and Status Register(BTINTEL_PCIE_CSR) */
>  #define BTINTEL_PCIE_CSR_BASE                  (0x000)
>  #define BTINTEL_PCIE_CSR_FUNC_CTRL_REG         (BTINTEL_PCIE_CSR_BASE + 0x024)
> @@ -737,6 +739,8 @@ struct btintel_pcie_data {
>         u32     boot_stage_cache;
>         u32     img_resp_cache;
>         u32     dbg_path_cache;
> +       bool    enable_ini;
> +       struct btintel_pcie_yoyo_ctx yoyo;
>
>         u32     cnvi;
>         u32     cnvr;
> diff --git a/drivers/bluetooth/btintel_pcie_debug.c b/drivers/bluetooth/btintel_pcie_debug.c
> new file mode 100644
> index 000000000000..0e933f4ec376
> --- /dev/null
> +++ b/drivers/bluetooth/btintel_pcie_debug.c
> @@ -0,0 +1,161 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Intel Bluetooth YoYo Debug Framework
> + *
> + * Copyright (C) 2026 Intel Corporation
> + *
> + * Runtime-configurable TLV-based debug collection framework for loading and
> + * parsing the optional YoYo firmware configuration used to enable debug
> + * regions, triggers, HCI commands, and configuration sets.
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <linux/unaligned.h>
> +#include <net/bluetooth/bluetooth.h>
> +#include "btintel_pcie_debug.h"
> +
> +/*
> + * Parse the optional YoYo firmware TLV stream and validate each record.
> + * This is the entry point for the runtime debug configuration payload.
> + */
> +static int btintel_pcie_yoyo_parse_tlv_buffer(struct btintel_pcie_yoyo_ctx *ctx,
> +                                             const u8 *buf, size_t buf_len)
> +{
> +       const struct btintel_pcie_tlv_hdr *tlv;
> +       const u8 *ptr = buf;
> +       size_t remaining = buf_len;
> +       u32 count = 0;
> +
> +       while (remaining >= sizeof(*tlv)) {
> +               size_t tlv_size;
> +               u32 type, len;
> +
> +               tlv = (const struct btintel_pcie_tlv_hdr *)ptr;
> +               type = get_unaligned_le32(&tlv->type);
> +               len = get_unaligned_le32(&tlv->length);
> +
> +               if (len > remaining - sizeof(*tlv)) {
> +                       BT_ERR("YoYo: tlv %u truncated (len=%u rem=%zu)", count,
> +                              len, remaining);
> +                       return -EBADMSG;
> +               }
> +               tlv_size = sizeof(*tlv) + len;
> +
> +               switch (type) {
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_INFO:
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_REGION:
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_TRIGGER:
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_HCMD:
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_CONFIG_SET:
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_BUF_ALLOC:
> +               case BTINTEL_PCIE_TLV_TYPE_DBG_PRESET_OVERRIDE:
> +                       BT_DBG("YoYo: valid tlv type 0x%x len=%u", type, len);
> +                       break;
> +               default: /* Log and continue, do not fail*/
> +                       BT_DBG("YoYo: unknown tlv type 0x%x len=%u", type, len);
> +                       break;
> +               }
> +
> +               ptr += tlv_size;
> +               remaining -= tlv_size;
> +               count++;
> +       }
> +
> +       /* If no TLVs were parsed, the YoYo binary is considered invalid */
> +       if (remaining || count == 0) {
> +               BT_ERR("YoYo: trailing %zu bytes after tlv stream", remaining);
> +               return -EBADMSG;
> +       }
> +
> +       BT_DBG("YoYo: parsed %u tlv's", count);
> +       return 0;
> +}
> +
> +/**
> + * btintel_yoyo_init - Initialize the YoYo context
> + * @ctx:   Pre-allocated context (typically embedded in driver data)
> + */
> +int btintel_pcie_yoyo_init(struct btintel_pcie_yoyo_ctx *ctx)
> +{
> +       if (!ctx)
> +               return -EINVAL;
> +
> +       memset(ctx, 0, sizeof(*ctx));
> +       INIT_LIST_HEAD(&ctx->region_list);
> +       INIT_LIST_HEAD(&ctx->trigger_list);
> +       INIT_LIST_HEAD(&ctx->hcmd_list);
> +       INIT_LIST_HEAD(&ctx->config_set_list);
> +
> +       /* set it to true after successful TLV parsing */
> +       ctx->enabled = false;
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(btintel_pcie_yoyo_init);
> +
> +/**
> + * btintel_yoyo_cleanup - Clean up the YoYo context
> + * @ctx:  YoYo context to clean up
> + */
> +void btintel_pcie_yoyo_cleanup(struct btintel_pcie_yoyo_ctx *ctx)
> +{
> +       if (!ctx)
> +               return;
> +
> +       ctx->enabled = false;
> +}
> +EXPORT_SYMBOL_GPL(btintel_pcie_yoyo_cleanup);
> +
> +/**
> + * btintel_yoyo_load_and_parse - Load ibt_debug_yoyo.bin and parse TLVs
> + * @ctx:  Initialized YoYo context
> + * @dev:  Device for firmware loading (typically &pdev->dev)
> + *
> + * Uses request_firmware_direct, since the YoYo binary
> + * is optional. On success, sets ctx->enabled.
> + */
> +int btintel_pcie_yoyo_load_and_parse(struct btintel_pcie_yoyo_ctx *ctx,
> +                                    struct device *dev)
> +{
> +       const struct firmware *fw;
> +       int ret;
> +
> +       if (!ctx)
> +               return -EINVAL;
> +
> +       ret = request_firmware_direct(&fw, BTINTEL_PCIE_YOYO_FW_NAME, dev);
> +       if (ret) {
> +               BT_WARN("YoYo: failed to load %s (%d)",
> +                       BTINTEL_PCIE_YOYO_FW_NAME, ret);
> +               return ret;
> +       }
> +
> +       /* Sanity check firmware size */
> +       if (fw->size < sizeof(struct btintel_pcie_tlv_hdr)) {
> +               release_firmware(fw);
> +               return -EBADMSG;
> +       }
> +
> +       BT_DBG("YoYo: loaded %s (%zu bytes)", BTINTEL_PCIE_YOYO_FW_NAME,
> +              fw->size);
> +
> +       ret = btintel_pcie_yoyo_parse_tlv_buffer(ctx, fw->data, fw->size);
> +       release_firmware(fw);
> +
> +       /* File Corruption / TLV validation failed */
> +       if (ret) {
> +               BT_ERR("YoYo: tlv parsing failed (%d)", ret);
> +               return ret;
> +       }
> +
> +       ctx->enabled = true;
> +
> +       BT_INFO("YoYo: feature enabled and configured");
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(btintel_pcie_yoyo_load_and_parse);
> +
> +MODULE_DESCRIPTION("Intel Bluetooth yoyo debug framework");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/bluetooth/btintel_pcie_debug.h b/drivers/bluetooth/btintel_pcie_debug.h
> new file mode 100644
> index 000000000000..b0b94c2a169d
> --- /dev/null
> +++ b/drivers/bluetooth/btintel_pcie_debug.h
> @@ -0,0 +1,77 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Intel Bluetooth YoYo Debug Framework
> + *
> + * Copyright (C) 2026 Intel Corporation
> + *
> + */
> +
> +#ifndef __BTINTEL_PCIE_DEBUG_H__
> +#define __BTINTEL_PCIE_DEBUG_H__
> +
> +#include <linux/list.h>
> +#include <linux/types.h>
> +#include <linux/device.h>
> +#include <linux/firmware.h>
> +
> +/* External YoYo binary file */
> +#define BTINTEL_PCIE_YOYO_FW_NAME      "intel/ibt_debug_yoyo.bin"
> +
> +/* TLV type codes */
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_INFO         0x1000005
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_BUF_ALLOC            0x1000006
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_HCMD         0x1000007
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_REGION               0x1000008
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_TRIGGER              0x1000009
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_CONFIG_SET           0x100000A
> +#define BTINTEL_PCIE_TLV_TYPE_DBG_PRESET_OVERRIDE      0x100000B
> +
> +/* TLV header */
> +struct btintel_pcie_tlv_hdr {
> +       __le32 type;
> +       __le32 length;
> +} __packed;
> +
> +/* Debug header common to all debug TLVs */
> +struct btintel_pcie_dbg_hdr {
> +       __le32 tlv_data_version;
> +       __le32 domain;
> +} __packed;
> +
> +/* Address/value pair */
> +struct btintel_pcie_addr_value {
> +       __le32 address;
> +       __le32 value;
> +} __packed;
> +
> +/*
> + * struct btintel_pcie_yoyo_ctx- Runtime state for YoYo debug configuration
> + * @enabled: Whether the loaded YoYo configuration passed validation
> + * @region_list: Parsed debug-region entries
> + * @trigger_list: Parsed debug-trigger entries
> + * @hcmd_list: Parsed HCI command entries
> + * @config_set_list: Parsed configuration-set entries
> + * @hdev: Associated HCI device; NULL until successful HCI registration
> + *
> + * Stores the validation state and parsed TLV data for the optional YoYo
> + * firmware configuration.
> + */
> +struct btintel_pcie_yoyo_ctx {
> +       bool                     enabled;
> +
> +       struct list_head         region_list;
> +       struct list_head         trigger_list;
> +       struct list_head         hcmd_list;
> +       struct list_head         config_set_list;
> +
> +       struct hci_dev           *hdev;
> +};
> +
> +int  btintel_pcie_yoyo_init(struct btintel_pcie_yoyo_ctx *ctx);
> +void btintel_pcie_yoyo_cleanup(struct btintel_pcie_yoyo_ctx *ctx);
> +
> +/* Load and parse the external .bin file */
> +int  btintel_pcie_yoyo_load_and_parse(struct btintel_pcie_yoyo_ctx *ctx,
> +                                     struct device *dev);
> +
> +#endif /* __BTINTEL_PCIE_DEBUG_H__ */
> --
> 2.53.0

There are quite a few issues flagged by sashiko:

https://sashiko.dev/#/patchset/20261013104416.26143-1-ajay.k.v%40intel.com

-- 
Luiz Augusto von Dentz