Skip to content
  • Takashi Iwai's avatar
    ALSA: intel8x0: Drop superfluous VM checks · 4926c804
    Takashi Iwai authored
    intel8x0 driver has the inside_vm check for skipping a buggy hardware
    workaround in the PCM pointer callback in the commit [228cf793:
    ALSA: intel8x0: Improve performance in virtual environment].  This was
    originally applied to all devices on known VMs, but the code was
    switched to use the PCI  ID matching for applying to only known
    devices (KVM and Parallels), in order to avoid applying wrongly to
    VT-d and other such cases, in the commit [7fb4f392
    
    : ALSA:
    intel8x0: improve virtual environment detection].
    
    Meanwhile, the original VM check was kept even after switching to the
    PCI ID matching.  It was partly because we weren't 100% sure whether
    we had covered all well, and partly because this would help
    identifying the issue once when a user of another VM hit the same
    problem or a regression.  Currently the VM check is used only for
    showing the kernel message that the VM-optimization isn't applied, and
    the VM check itself doesn't change the actual driver behavior at all.
    
    Despite the relatively safe driver behavior, the code caught attention
    of developers badly and brought many confusion / misunderstanding.
    Since we've got neither regression nor enhancement report for other
    VMs for five years long, it's likely safe to drop this superfluous VM
    check now.
    
    The module option is still kept, so if a user still needs to adjust,
    it can be applied as was.
    
    Acked-by: default avatarKonstantin Ozerkov <kozerkov@parallels.com>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    4926c804