Hello, Joe Jin.

Joe Jin wrote:
> On my pc(Dell OptiPlex GX620), while boot up it by 2.6.18, the next
> info always report:
> ===========================================
> ata2: port is slow to respond, please be patient
> ata2: port failed to respond (30 secs)
> ata2: SRST failed (status 0xFF)
> ata2: SRST failed (err_mask=0x100)
> ata2: softreset failed, retrying in 5 secs
> ata2: SRST failed (status 0xFF)
> ata2: SRST failed (err_mask=0x100)
> ata2: softreset failed, retrying in 5 secs
> ata2: SRST failed (status 0xFF)
> ata2: SRST failed (err_mask=0x100)
> ata2: reset failed, giving up
> ===========================================

I see.

> 00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE
> Controller (rev 01) (prog-if 8a [Master SecP PriP])
>        Subsystem: Dell: Unknown device 01ad
>        Flags: bus master, medium devsel, latency 0, IRQ 169
>        I/O ports at <ignored>
>        I/O ports at <ignored>
>        I/O ports at <ignored>
>        I/O ports at <ignored>
>        I/O ports at ffa0 [size=16]
> 00: 86 80 df 27 05 00 88 02 01 8a 01 01 00 00 00 00
> 10: f1 01 00 00 f5 03 00 00 71 01 00 00 75 03 00 00
> 20: a1 ff 00 00 00 00 00 00 00 00 00 00 28 10 ad 01
> 30: 00 00 00 00 00 00 00 00 00 00 00 00 0b 01 00 00
> 
> 00:1f.2 IDE interface: Intel Corporation 82801GB/GR/GH (ICH7 Family)
> Serial ATA Storage Controller IDE (rev 01) (prog-if 8f [Master SecP
> SecO PriP PriO])
>        Subsystem: Dell: Unknown device 01ad
>        Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 217
>        I/O ports at fe00 [size=8]
>        I/O ports at fe10 [size=4]
>        I/O ports at fe20 [size=8]
>        I/O ports at fe30 [size=4]
>        I/O ports at fea0 [size=16]
>        Capabilities: <available only to root>
> 00: 86 80 c0 27 07 00 b0 02 01 8f 01 01 00 00 00 00
> 10: 01 fe 00 00 11 fe 00 00 21 fe 00 00 31 fe 00 00
> 20: a1 fe 00 00 00 00 00 00 00 00 00 00 28 10 ad 01
> 30: 00 00 00 00 70 00 00 00 00 00 00 00 05 03 00 00

Can you post the result of the following command.

# lspci -nvvvxxx -s 00:1f.

> through traced the code, and found which caused it:
> at scsi_eh_[port_no] kernel thread, it should reset the bus, before 
> reset it,
> it never check it if have a device. if it should skip it?
> thanks

Hmmm... Not really.  The controller shouldn't report BSY for empty 
channel.  There's a notable exception where PATA pins aren't properly 
pulled resulting in 0xff status on empty channels.  IDE handles the case 
specially but libata doesn't yet.  Can you try the attached patch?

-- 
tejun