Linux 5.14 Drops Its Legacy IDE Code
Linux's legacy IDE driver code has been deprecated since 2019 and planned for removal in 2021. This is about clearing out the legacy IDE code while IDE driver support remains available via the more modern libata-based code in the kernel. This legacy code is what was commonly associated with the older /dev/hdX devices. Most systems and Linux users have likely not used this legacy code in more than one decade.
Earlier this year was talk of going ahead with the legacy IDE removal The final obstacle was recently resolved with moving old Motorola 68000 system support to libata and off that legacy IDE code. Thus the legacy IDE code removal was cleared to proceed without sacrificing (old) hardware support.
On Monday the removal happened with the nuking of drivers/ide. The old code is removed and it also now allows for future cleaning in the kernel's block subsystem for code that was only there because of the old IDE code.
This removal led to lightening the kernel by more than 41,000 lines of code.