hdparm "Get/set IDE 32-bit IO setting" returns "IO_support =-2130557184 (???)" error

Question

I'm trying to debug my Macbook Air SSD but am getting IO_support errors.

hdparm -c /dev/sda

/dev/sda:
 IO_support    =-2130557184 (???)

hdparm -c0 /dev/sda

/dev/sda:
 setting 32-bit IO_support flag to 0
 IO_support    =-2130557184 (???)

hdparm -c1 /dev/sda

/dev/sda:
 setting 32-bit IO_support flag to 1
 HDIO_SET_32BIT failed: Invalid argument
 IO_support    =-2130557184 (???)

So then I attempt to Secure Erase my SSD anyway which seems to work.

sh-4.1# hdparm --user-master u --security-set-pass Eide /dev/sda

 security_password="Eide"

 /dev/sda:
 Issuing SECURITY_SET_PASS command, password="Eide", user=user, mode=high

sh-4.1# hdparm --user-master u --security-erase Eide /dev/sda

  security_password="Eide"

  /dev/sda:
  Issuing SECURITY_ERASE command, password="Eide", user=user

sh-4.1# hdparm --user-master u --security-set-pass Eide /dev/sda

  security_password="Eide"

  /dev/sda:
  Issuing SECURITY_SET_PASS command, password="Eide", user=user, mode=high

sh-4.1# hdparm --user-master u --security-erase-enhanced Eide /dev/sda

  security_password="Eide"

  /dev/sda:
  Issuing SECURITY_ERASE command, password="Eide", user=user

But when I query the 32-bit IO setting...

hdparm -c /dev/sda

/dev/sda:
 IO_support    =-2130557184 (???)

After the two ATA security erase commands completed, drive identification shows:

hdparm -i /dev/sda

/dev/sda:

 Model=APPLE SSD TS128C, FwRev=CJAA0201, SerialNo=71BA50Q5K6IK
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
 BuffType=unknown, BuffSize=unknown, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=236978176
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio3 pio4 
 DMA modes:  mdma0 mdma1 mdma2 
 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 
 AdvancedPM=yes: unknown setting WriteCache=enabled
 Drive conforms to: Unspecified:  ATA/ATAPI-3,4,5,6,7

 * signifies the current active mode

nb. I have some questions about that output as well which aren't as important (I don't think?) as the "inappropriate IO control" problem.

1. Does that geometry config even make sense? I thought there are supposed to be 255 heads so something like xxx/255/63 ?
2. SectSize=0 ? Shouldn't it be 512?
3. Why is BuffType and BuffSize "unknown"?
4. Why APM setting "unknown"?
5. Why is drive conforming to "Unspecified ATA/ATAPI" standard?

Trying to set using_DMA flag fails:

hdparm -d /dev/sda

/dev/sda:
 HDIO_GET_DMA failed: Inappropriate ioctl for device

hdparm -d1 /dev/sda

/dev/sda:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Inappropriate ioctl for device
 HDIO_GET_DMA failed: Inappropriate ioctl for device

What is the "appropriate ioctl"?

Resetting the drive doesn't work.

hdparm -w /dev/sda

/dev/sda:
 resetting drive
 HDIO_DRIVE_RESET failed: Invalid argument

hdparm --dco-identify /dev/sda

/dev/sda:
DCO Revision: 0x0002
The following features can be selectively disabled via DCO:
    Transfer modes:
         mdma0 mdma1 mdma2
         udma0 udma1 udma2 udma3 udma4 udma5
    Real max sectors: 236978176
    ATA command/feature sets:
         SMART self_test error_log security HPA
         selective_test
    SATA command/feature sets:
         interface_power_management

hdparm --yes-i-know-what-i-am-doing --dco-restore /dev/sda

/dev/sda:
 issuing DCO restore command
 HDIO_DRIVE_CMD(dco_restore) failed: Input/output error

Any observations, questions, hints, answers appreciated cheers!