406-custom-fan-curve.md: CFC003 description

Signed-off-by: Filip Gołaś <[email protected]>

docs/unified-test-documentation/dasharo-performance/406-custom-fan-curve.md

@@ -196,3 +196,68 @@ Example check for 30°C and 79 PWM values:
 
 Values `expected_speed` and `actual_speed` are strongly similar. This means
 that the fan control is set correctly.
+
+## CFC003.001 Custom fan curve OFF profile measure (Ubuntu)
+
+**Test description**
+
+The fan has been configured to follow a custom curve. This test aims to verify
+that the fan curve is configured correctly in the OFF profile and the
+fan does not spin, or barely spins, which depends on the type of the fan.
+
+The test requires the device to use have the IT87 EC. For example Protectli
+VP66xx, VP32xx and VP2420.
+
+**Test configuration data**
+
+1. `FIRMWARE` = Dasharo
+
+**Test setup**
+
+1. Proceed with the
+   [Test cases common documentation](#test-cases-common-documentation) section.
+1. Install `stress-ng` on the DUT.
+1. Install `lm-sensors` on the DUT
+
+**Test steps**
+
+1. Power on the DUT.
+1. While the DUT is booting, hold the `BIOS_SETUP_KEY` to enter the UEFI Setup
+   Menu.
+1. Enter the `Dasharo System Features` menu using the arrow keys and Enter.
+1. Enter the `Power Management Options` submenu.
+1. Verify that the `Fan profile` field is set to `OFF` - if not, using
+   the arrow keys and `Enter`, choose the `Performance` option.
+1. Press `F10` to save the changes.
+1. If necessary - press `Y` to confirm saving the changes.
+1. Go back to the main menu using the `ESC` key.
+1. Select the `Reset` option to apply the settings and reboot.
+1. Boot into the system.
+1. Log into the system by using the proper login and password.
+1. Open the terminal window and run the following command to load the EC sensor
+kernel module:
+
+    ```bash
+    sudo modprobe it87 force_id=0x8786
+    ```
+
+1. Open the terminal window and run the following command to run a stress test
+on the CPU:
+
+    ```bash
+    stress-ng --cpu 16 --timeout 30m
+    ```
+
+1. Open the terminal window and run the following command to get the
+   temperature and fans' RPM:
+
+    ```bash
+    watch -n1 "sensors it8786-isa-0a20 | grep -E 'fan|temp1'"
+    ```
+
+1. Note the results.
+
+**Expected result**
+
+The fan PWM should be equal to `0` or be low and don't increase with temperature
+, for example ~`250` RPM. This depends on the model of the fan used.