> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Debug with sysfs or debugfs nodes

To identify the status or update the state, use the `sysfs` and `debugfs` nodes.

Mount `debugfs` to ensure that the `debugfs` file system is accessible for the debug nodes.

```bash theme={null}
mount -t debugfs none /sys/kernel/debug
```

## UFS device state commands

| Required UFS device state information                          | Command                                                                                                         |
| -------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- |
| Check PA/DL error count                                        | `cat /sys/kernel/debug/ufshcd/1d84000.ufshc/stats`                                                              |
| Read UFS device gating delay, in ms                            | `cat /sys/devices/platform/soc@0/1d84000.ufshc/clkgate_delay_ms`                                                |
| Read UFS device clocks current frequency at given point        | `cat /sys/devices/platform/soc@0/1d84000.ufshc/devfreq/1d84000.ufshc/cur_freq`                                  |
| Read UFS device I/O scheduler details                          | `cat /sys/devices/platform/soc@0/1d84000.ufshc/devfreq/1d84000.ufshc/governor`                                  |
| Read UFS device min frequency during clock scale down          | `cat /sys/devices/platform/soc@0/1d84000.ufshc/devfreq/1d84000.ufshc/min_freq`                                  |
| Read UFS device max frequency during clock scale up            | `cat /sys/devices/platform/soc@0/1d84000.ufshc/devfreq/1d84000.ufshc/max_freq`                                  |
| Read UFS device state active or sleep                          | `cat /sys/devices/platform/soc@0/1d84000.ufshc/power_info/dev_pm`                                               |
| Read UFS device gear information such as HS\_GEAR3, HS\_GEAR4  | `cat /sys/devices/platform/soc@0/1d84000.ufshc/power_info/gear`                                                 |
| Read UFS device number of lanes                                | `cat /sys/devices/platform/soc@0/1d84000.ufshc/power_info/lane`                                                 |
| Read UFS device link state, ACTIVE or HIBERN8                  | `cat /sys/devices/platform/soc@0/1d84000.ufshc/power_info/link_state`                                           |
| Read UFS device rate information such as Rate A or B           | `cat /sys/devices/platform/soc@0/1d84000.ufshc/power_info/rate`                                                 |
| Read UFS device descriptor information                         | `ls /sys/devices/platform/soc@0/1d84000.ufshc/device_descriptor`                                                |
| Read UFS device health descriptor information                  | `ls /sys/devices/platform/soc@0/1d84000.ufshc/health_descriptor`                                                |
| Read UFS device runtime status information active or suspended | `cat /sys/devices/platform/soc@0/1d84000.ufshc/power/runtime_status`                                            |
| Find and/or modify the SPM/RPM level                           | `cat /sys/devices/platform/soc@0/1d84000.ufshc/rpm_lvl` `cat /sys/devices/platform/soc@0/1d84000.ufshc/spm_lvl` |

## SD card state commands

| Required SD card state information                                | Command                                                                      |
| ----------------------------------------------------------------- | ---------------------------------------------------------------------------- |
| Read SD card error stats information                              | `cat /sys/kernel/debug/mmc1/err_stats`                                       |
| Read SD card latest error state details                           | `cat /sys/kernel/debug/mmc1/err_state`                                       |
| Check the current running clock details                           | `cat /sys/kernel/debug/mmc1/clock`                                           |
| Read the SD card runtime status information (active or suspended) | `cat /sys/devices/platform/soc@0/87c4000.sdhci/power/runtime_status`         |
| Read SD card auto suspend delay time                              | `cat /sys/devices/platform/soc@0/87c4000.sdhci/power/autosuspend_delay_ms`   |
| Read SD card runtime active time                                  | `cat /sys/devices/platform/soc@0/87c4000.sdhci/power/runtime_active_time`    |
| Read SD card runtime suspend time                                 | `cat /sys/devices/platform/soc@0/87c4000.sdhci/power/runtime_suspended_time` |
| Read SD card uevent details                                       | `cat /sys/devices/platform/soc@0/87c4000.sdhci/uevent`                       |

## NVMe state commands

| Required NVMe card state information                                                          | Command                                              |
| --------------------------------------------------------------------------------------------- | ---------------------------------------------------- |
| View device model name                                                                        | `cat /sys/class/nvme/nvme0/model`                    |
| View device serial number                                                                     | `cat /sys/class/nvme/nvme0/serial`                   |
| View current firmware version                                                                 | `cat /sys/class/nvme/nvme0/firmware_rev`             |
| View namespace identifier                                                                     | `cat /sys/class/nvme/nvme0/nvme0n1/nsid`             |
| View namespace size                                                                           | `cat /sys/class/nvme/nvme0/nvme0n1/size`             |
| View the offset in bytes to align the start of the NVMe namespace to the optimal I/O boundary | `cat /sys/class/nvme/nvme0/nvme0n1/alignment_offset` |
| View queue depth                                                                              | `cat /sys/class/nvme/nvme0/queue_count`              |

## eMMC node commands

| Description                              | Command                                                                         |
| ---------------------------------------- | ------------------------------------------------------------------------------- |
| eMMC error stats information             | `cat /sys/kernel/debug/mmc0/err_stats`                                          |
| eMMC latest error state details          | `cat /sys/kernel/debug/mmc0/err_state`                                          |
| Current running clock details of an eMMC | `cat /sys/kernel/debug/mmc0/clock`                                              |
| eMMC runtime status information          | `cat /sys/devices/platform/soc@0/<sdhci_addr>.mmc/power/runtime_status`         |
| eMMC auto suspend delay time             | `cat /sys/devices/platform/soc@0/<sdhci_addr>.mmc/power/autosuspend_delay_ms`   |
| eMMC runtime active time                 | `cat /sys/devices/platform/soc@0/<sdhci_addr>.mmc/power/runtime_active_time`    |
| eMMC runtime suspend time                | `cat /sys/devices/platform/soc@0/<sdhci_addr>.mmc/power/runtime_suspended_time` |
| eMMC uevent details                      | `cat /sys/devices/platform/soc@0/<sdhci_addr>.mmc/uevent`                       |

<Note>
  Update the `<sdhc1_address>` values based on the SDHCI physical address of the chip products.

  Example:

  * Qualcomm Dragonwing™ IQ-615: `7c4000`
  * Qualcomm Dragonwing™ IQ-8275: `87c4000`
  * Qualcomm Dragonwing™ IQ-9075: `7c4000`
</Note>