More AIC-7895 Info...

[Doug Ledford]

On 20-Jan-98 Kolin E. Hand wrote:
>I also have a Tyan Thunder II and am getting a continuous resets and have
>observed the "No BIOS" messages...
>
>The Adaptec BIOS is 1.32 and the Thunder BIOS is 1.16.
>
>Linux kernel is 2.0.33.
>
>Aic7xxx driver loaded into the kernel, i.e. not as a module.
>
>I get the following with "verbose:0xfff":
>
>aic7xxx: <Adaptec AIC-7895 Ultra SCSI host adapter> at PCI 15/1
>aic7xxx: Loading serial EEPROM...
>aic7xxx: No SEEPROM available; using defaults.
>aic7xxx: Using leftover BIOS values.
>aic7xxx: <Adaptec AIC-7895 Ultra SCSI host adapter> at PCI 15/0
>aic7xxx: Loading serial EEPROM...
>aic7xxx: No SEEPROM available; using defaults.
>aic7xxx: Using leftover BIOS values.

I'm hoping (fingers crossed) that a change I made to the load_seeprom
routine will allow your seeprom to be read.

>
>For the reset issue, here is more info...
>
>I have the following, all on Channel A, nothing on Channel B:
>
>       ID 0:  Seagate Barracuda (ST-34371W)
>       ID 3:  NEC CDROM Drive (on the narrow channel)
>       ID 6:  IOMEGA ZIP Drive (also on the narrow channel but on
>              an external connector that I purchased, termination
>              enabled on the ZIP drive.
>
>Here's the dmesg output for the devices:
>
>  (scsi0:0:0:0) Synchronous at 20.0MHz, offset 8.
>    Vendor: SEAGATE   Model: ST34371W          Rev: 0484
>    Type:   Direct-Access                      ANSI SCSI revision: 02
>  Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
>  (scsi0:0:3:0) Synchronous at 20.0MHz, offset 8.
>    Vendor: NEC       Model: CD-ROM DRIVE:464  Rev: 1.04
>    Type:   CD-ROM                             ANSI SCSI revision: 02
>  Detected scsi CD-ROM sr0 at scsi0, channel 0, id 3, lun 0
>    Vendor: IOMEGA    Model: ZIP 100           Rev: R.41
>    Type:   Direct-Access                      ANSI SCSI revision: 02
>  Detected scsi removable disk sdb at scsi0, channel 0, id 6, lun 0
>
>What I am observing is that Channel A is scanned, apparently successfully,
>Channel B is then scanned, also apparently successfully.  I get a message
>similar to:
>
>       (scsi1:0:-1:-1) Scanning channel for devices.
>       (scsi1:-1:-1:-1) Allocating initial 30 SCB structures.
>
>Then the reset looping begins...  I get this sequence repeated
>indefinitely...
>
>(scsi0:0:0:0) No active SCB for reconnecting target - Issuing BUS DEVICE
>RESET.
>(scsi0:0:0:0)         SAVED_TCL=0x0, ARG_1=0xff, SEQADDR=0x103
>(scsi0:0:0:-1)  Reset device, active_scb 0
>(scsi0:0:0:-1)  Cleaning up status information and delayed_scbs.
>(scsi0:0:0:-1)  Cleaning QINFIFO
>(scsi0:0:0:-1)  Cleaning waiting_scbs.
>(scsi0:0:0:-1)  Cleaning waiting for selection list.
>(scsi0:0:0:0:tag29)  matches search criteria (scsi0:0:0:-1:tag255)
>(scsi0:0:0:-1)  Bus Device Reset delivered.
>(scsi0:0:0:0)  Aborting scb 29
>(scsi0:0:0:0)  Using Wide (16 bit) transfers.
>(scsi0:0:0:0)  Synchronous at 20MHz, offset 8.
>...
>
>But here's the rub, this happens when I do not have a ZIP disk in the ZIP
>drive...  When I load a disk, then reboot, the reset loops do not occur.
>The system boots successfully.

Hmmm....of course, one difference between you and the other report is that
you are actually completing the bus scan on Channel B, it isn't until the
bus scan is complete and the system tries to talk to the devices that things
go wierd.  Also, theoretically, inserting a zip disk should not effect the
Seagate disk, which is what the sequencer is complaining about reconnections
with.  I'll have to think about what may be going on here.  It'll probably
have to wait until after my next version so I can make sure nothing I've
fixed so far has an impact on this.

>
>Another note, the dmesg info reports both channels, A and B, as Ultra
>Wide channels, while when I cat either /proc/scsi/aic7xxx/0 or 1, they
>list both channels as Ultra Narrow...  

Found and fixed this one (it was benign, just checking the wrong variable
during a printk).

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E-Mail: Doug Ledford <dledford at dialnet.net>
Date: 20-Jan-98
Time: 13:07:31
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