Deinitializing SPI bus 'breaks' OV2640 (IDFGH-6877)

[JVKran]

Environment

• Development Kit: ESP32-S3-DevKitC and ESP32-CAM (AiThinker)
• Kit version: V1-N8R2
• Module or chip used: ESP32-S3-WROOM
• IDF version: v4.4
• Build System: idf.py
• Compiler version: xtensa-esp32-elf-gcc.exe (crosstool-NG esp-2021r2-patch2) 8.4.0
• Operating System: Windows 10
• (Windows only) environment type: Plain Command Prompt.
• Using an IDE?: Visual Studio Code with ESP-IDF extension
• Power Supply: USB

Problem Description

When using hardware which consists of an SD-card reader and an OV2640 connected to an ESP32-S3 DevKitC I'm unable to use the OV2640 after unmounting the SD-card. I've narrowed the problem down to spi_bus_free(host.slot); at line 240. When that function isn't called, the camera remains usable.

Expected Behavior

The OV2640 (which I'm using through the esp32-camera component) still works after deinitializing the SPI bus.

Actual Behavior

The OV2640 only prints cam_hal: Failed to get the frame on time!.

Steps to reproduce

1. Use the attached zip for a complete runnable project, or the GIST linked underneath.
2. Select the ESP32-S3 as build target.
3. Build, flash and monitor the project.
4. Observe taking pictures after spi_bus_free(host.slot); doesn't work.
5. Change build target to ESP32.
6. Build, flash and monitor the project.
7. Observe taking pictures after spi_bus_free(host.slot); still works.

Code to reproduce this issue

See code in GIST or project in sdspi.zip.

[JVKran]

No longer relevant.