Re: [SCSI] sun3x_esp: convert to esp_scsi

Re: [SCSI] sun3x_esp: convert to esp_scsi

[Kars de Jong]

On vr, 2008-02-08 at 09:33 +0100, Geert Uytterhoeven wrote:
> On Fri, 8 Feb 2008, Linux Kernel Mailing List wrote:
> > Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0bb67f181834044db6e9b15c7d5cc3cce0489bfd
> > Commit:     0bb67f181834044db6e9b15c7d5cc3cce0489bfd
> > Parent:     f8d9d654fcc7dd87f5d0b222e233eaab15d650c4
> > Author:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > AuthorDate: Fri Feb 1 00:13:34 2008 +0100
> > Committer:  James Bottomley <James.Bottomley@HansenPartnership.com>
> > CommitDate: Thu Feb 7 18:02:33 2008 -0600
> > 
> >     [SCSI] sun3x_esp: convert to esp_scsi
> >     
> >     Converted sun3x_esp driver to use esp_scsi.c
> >     
> >     Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> >     Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> > ---
> >  drivers/scsi/Kconfig     |    1 +
> >  drivers/scsi/Makefile    |    2 +-
> >  drivers/scsi/sun3x_esp.c |  708 +++++++++++++++++++++-------------------------
> >  3 files changed, 318 insertions(+), 393 deletions(-)
> 
> But the first one is back! Thank you, Thomas!

Thomas, can't you use ioreadxx() and friends instead of rolling your own
memory mapped I/O handlers? readxx() and friends are only to be used on
PCI-like buses.

Unfortunately, a simple conversion like this didn't work for me on the
Blizzard SCSI IV. The driver gets stuck when probing devices:

esp: esp0, regs[80ea8000:80eb0000] irq[2]
esp: esp0 is a 53CF94/96-2, 40 MHz (ccf=0), SCSI ID 7
scsi0 : esp
ESP: tgt[0] lun[0] scsi_cmd [ 12 00 00 00 24 00 ]
ESP: start data addr[78e76590] len[36] write(1)
ESP: data done flgs[1] sent[36]
ESP: Command done status[0] message[0]
ESP: tgt[0] lun[0] scsi_cmd [ 12 00 00 00 86 00 ]
ESP: start data addr[78e76590] len[134] write(1)
ESP: data done flgs[1] sent[134]
ESP: Command done status[0] message[0]
scsi 0:0:0:0: Direct-Access     QUANTUM  FIREBALL_TM2110S 300N PQ: 0 ANSI: 2
 target0:0:0: Beginning Domain Validation
ESP: tgt[0] lun[0] scsi_cmd [ 12 00 00 00 86 00 ]
ESP: Got msgin byte 4
ESP: Disconnecting tgt[0] tag[20:0]
ESP: reconnect tag, IRQ(0:10:97), <3>esp: esp0: Reconnect IRQ2 timeout
ESP: esp_schedule_reset() from 00127ad2
 target0:0:0: Domain Validation Initial Inquiry Failed
 target0:0:0: Ending Domain Validation
ESP: tgt[1] lun[0] scsi_cmd [ 12 00 00 00 24 00 ]
ESP: tgt[2] lun[0] scsi_cmd [ 12 00 00 00 24 00 ]
ESP: Got msgin byte 7
ESP: Sending message [ 06 ]
...
ESP: Got msgin byte 7
ESP: Sending message [ 06 ]
...

The "Reconnect IRQ2 timeout" thing seemed wrong, so I modified it to
never timeout there (perhaps the timer was a bit short on m68k). This
causes it to get completely stuck, so the chip is apparently not in the
mood to generate any interrupt ever. I wonder whether this is because a
DMA operation is done with only 2 bytes...
The Blizzard DMA engine is rather simplistic (no byte counters). It's
also undocumented.

The old driver used to use PIO for small transfers (like message in and
SCSI commands). David, any ideas on this?


Kind regards,

Kars.

Re: [SCSI] sun3x_esp: convert to esp_scsi

[Thomas Bogendoerfer]

On Sun, Feb 10, 2008 at 10:38:15AM +0100, Kars de Jong wrote:
> Thomas, can't you use ioreadxx() and friends instead of rolling your own
> memory mapped I/O handlers?

well, at least ioread32be/iowrite32be are looking promising, but a quick
grep didn't show them for m68k.

> readxx() and friends are only to be used on PCI-like buses.

hmm, afaik readxx/writexx is not directly related to PCI. It's
like ioread/iowrite to access iomapped address space. The difference
to ioread/iowrite is that it doesn't support PCI IO space.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea.                                                [ RFC1925, 2.3 ]

Re: [SCSI] sun3x_esp: convert to esp_scsi

[James Bottomley]

On Mon, 2008-02-11 at 12:24 +0100, Thomas Bogendoerfer wrote:
> On Sun, Feb 10, 2008 at 10:38:15AM +0100, Kars de Jong wrote:
> > Thomas, can't you use ioreadxx() and friends instead of rolling your own
> > memory mapped I/O handlers?
> 
> well, at least ioread32be/iowrite32be are looking promising, but a quick
> grep didn't show them for m68k.

Someone could submit a patch ...

> > readxx() and friends are only to be used on PCI-like buses.
> 
> hmm, afaik readxx/writexx is not directly related to PCI. It's
> like ioread/iowrite to access iomapped address space. The difference
> to ioread/iowrite is that it doesn't support PCI IO space.

That's correct ... at least that's the meaning we've ascribed on other
architectures I've worked on. Any ioremap'd memory area can be accessed
by readX/writeX.  The current list of Buses I know it works on is MCA,
EISA, GSC, Runway ... in addition to PCI.

James