git: ahci: remove broken AHCI_COALESCE dead code

[Matthew Dillon]

commit f18d92f9f9526246d6fdf1726fb564bb827395d1
Author: Abdelkader Boudih <dragonflybsd at seuros.com>
Date:   Thu May 7 11:21:24 2026 +0000

    ahci: remove broken AHCI_COALESCE dead code
    
    Remove the never-compiled AHCI Command Completion Coalescing
    implementation.  The code had multiple bugs (missing closing paren,
    bare printf instead of device_printf, OpenBSD DEVNAME macro
    incompatible with DragonFly newbus) and the approach is
    fundamentally wrong for general-purpose I/O.
    
    Hardware CCC delays every low queue-depth completion by the full
    timeout value, destroying filesystem metadata latency on single
    I/O operations that must wait for the coalescing window to expire.

Summary of changes:
 sys/dev/disk/ahci/ahci.c        | 36 ------------------------------------
 sys/dev/disk/ahci/ahci.h        | 11 -----------
 sys/dev/disk/ahci/ahci_attach.c | 37 +------------------------------------
 3 files changed, 1 insertion(+), 83 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/f18d92f9f9526246d6fdf1726fb564bb827395d1


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