>> > I updated the proposed patch in PR/21531 to -current and tested
>> > on my laptop (ThinkPad X31), which worked fine.
>> 
>> Applied it to my own machine (X30) with current
>> (1.6W), works fine. Will tell if it explodes :o)
>
>Thanks for testing.  My concern is that I'm not sure whether
>it's generic enough for all ATA/IDE drives.  The document which
>the original author points out in the PR is IBM drives' manual.
>My laptop uses an IBM drive (IC25N040ATCS04-0) and it's ok.
>
>In my case, the sound of harddrive shutdown become differnt
>after applying the patch.

Thank you for catch-up and testing.  I had ftp'd and checked
ATA-2/3/4 draft spec before I wrote the patch, so I believe
recent ATA drives shall be work.

My laptop (ThinkPad X31) uses a TOSHIBA drive, mostly ok.

wd0 at pciide0 channel 0 drive 0: <TOSHIBA MK4019GAX>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 38154 MB, 77520 cyl, 16 head, 63 sec, 512 bytes/sect x 78140160 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using DMA data transfers)

I have a CompactFlash, it has missing PM feature, ignored by the patch.

wd1 at wdc0 channel 0 drive 0: <TOSHIBA THNCF256MBA>
wd1: drive supports 1-sector PIO transfers, LBA addressing
wd1: 244 MB, 978 cyl, 16 head, 32 sec, 512 bytes/sect x 500736 sectors

I said mostly ok...  In my laptop environment, rerely, freezes when
shutdown.  Cause is not known. ;(