scsi error -> hang

scsi error -> hang

[Mat Loikkanen]

I'm trying to track down why Libata/SCSI is hanging after an error -- in
this case a result from a ATAPI device to a "test unit ready" packet cmd.
The sequence of events are as follows (HSATA is my driver).  My ISR gets
called when the error (status=0x51/error=0x64) is received by my host
controller;  my ISR ends up calling qc_complete.  An error is reported by
the scsi error handler kernel thread.  I'm using 2.6.9

ata_scsi_queuecmd
ata_scsi_dump_cdb: CDB (1:0,0,0) 00 00 00 00 00 00 00 00 00
ata_scsi_translate
atapi_xlat
HSATA : <6>hsata_qc_prep: not doing DMA - exiting
ata_qc_issue_prot: ATA_PROT_ATAPI_NODATA
ata_tf_load_mmio: feat 0x0 nsect 0x0 lba 0x0 0x0 0x20
ata_tf_load_mmio: device 0xA0
ata_exec_command_mmio: ata1: cmd 0xA0        <<ATAPI PACKET cmd>>
ata_scsi_translate: EXIT
atapi_packet_task: ENTER
atapi_packet_task: send cdb                  <<"test unit ready" (0x00)
cmd>>
HSATA : hsata_isr: <3>STATUS ERROR (0x51)
HSATA : hsata_isr: <3>ERROR REG = 0x64
HSATA : <6>hsata_isr: INTERRUPT ISR NODATA irq=21
ata_qc_complete   <<called as result of interrupt>>
HSATA : <4>hsata_scsi_error WARNING: uid=1 tid=-1
ata_scsi_error: ENTER                       <<.eh_strategy_handler>>
HSATA : <4>hsata_eng_timeout WARNING: id=1 magic=13
HSATA : <3>hsata_eng_timeout ERROR: ata1: BUG: timeout without command,
exiting
ata_scsi_error: EXIT

Any ideas to point me in the right direction?  I saw another thread on scsi
errors and hanging and decrementing ->host_failed in ata_scsi_error(), which
my version of libata-scsi does.

Thanks!

-mat
 
Mat Loikkanen
Synopsys, Inc.