Hello, Cliff.

Cliff Wickman wrote:
> I've run into a problem with the ATA SCSI disk driver when running in a
> kdump dump-capture kernel.
> 
> I'm running on 2-processor x86_64 box.  It has 2 scsi disks, /dev/sda and
> /dev/sdb
> 
> My kernel is 2.6.22, and built to be a dump capturing kernel loaded by kexec.
> When I boot this kernel by itself, it finds both sda and sdb.
> 
> But when it is loaded by kexec and booted on a panic it only finds sda.
> 
> Any ideas from those familiar with the ATA driver?
> 
> 
> -Cliff Wickman
>  SGI
> 
> 
> I put some printk's into it and get this:
> 
> Standalone:
> 
>                                                    [nv_adma_error_handler]
> cpw: ata_host_register probe port 1 (error_handler:ffffffff81348625)
> cpw: ata_host_register call ata_port_probe
> cpw: ata_host_register call ata_port_schedule
> cpw: ata_host_register call ata_port_wait_eh
> cpw: ata_port_wait_eh entered
> cpw: ata_port_wait_eh, preparing to wait
> ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> cpw: ata_dev_configure entered
> cpw: ata_dev_configure testing class
> cpw: ata_dev_configure class is ATA_DEV_ATA
> ata2.00: ATA-6: ST3200822AS, 3.01, max UDMA/133
> ata2.00: 390721968 sectors, multi 16: LBA48
> cpw: ata_dev_configure exiting
> cpw: ata_dev_configure entered
> cpw: ata_dev_configure testing class
> cpw: ata_dev_configure class is ATA_DEV_ATA
> cpw: ata_dev_configure exiting
> cpw: ata_dev_set_mode printing:
> ata2.00: configured for UDMA/133
> cpw: ata_port_wait_eh, finished wait
> cpw: ata_port_wait_eh exiting
> cpw: ata_host_register done with probe port 1
> 
> 
> When loaded with kexec and booted on a panic:
> 
> cpw: ata_host_register probe port 1 (error_handler:ffffffff81348625)
> cpw: ata_host_register call ata_port_probe
> cpw: ata_host_register call ata_port_schedule
> cpw: ata_host_register call ata_port_wait_eh
> cpw: ata_port_wait_eh entered
> cpw: ata_port_wait_eh, preparing to wait
> ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> cpw: ata_port_wait_eh, finished wait
> cpw: ata_port_wait_eh exiting
> cpw: ata_host_register done with probe port 1

Hmmm.. PHY is up but for some reason libata thought there was no device
there.  Can you try the attached patch and report the result?

-- 
tejun