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Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' co
From: |
Hannes Reinecke |
Subject: |
Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion |
Date: |
Thu, 25 Nov 2010 10:06:44 +0100 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.15) Gecko/20101026 SUSE/3.0.10 Thunderbird/3.0.10 |
On 11/25/2010 10:01 AM, Benjamin Herrenschmidt wrote:
> On Thu, 2010-11-25 at 09:50 +0100, Gerd Hoffmann wrote:
>> On 11/25/10 09:46, Benjamin Herrenschmidt wrote:
>>
>>> So far tho, it appears that I can (at least with scsi-disk) rely on
>>> always been eventually called with SCSI_REASON_DONE so my code (and
>>> maybe the usb-msd code too, I haven't verified) relies on that to
>>> complete requests... Is that incorrect ?
>>
>> Yes.
>
> Well, so far it works :-) But I suppose I must be lucky.. I must admit
> that it's very unclear how that SCSI "stack" is meant to be used from
> the HBA standpoint.
>
> Right now, I've somewhat come up with:
>
> - client request occurs
> - call device send_command()
> - if result is 0, assume my complete() was called with
> SCSI_REASON_DONE
> - else, use sign of result for transfer direction, store the
> absolute value as the total expected transfer len and call
> the device scsi_data_read()/write() and wait for complete()
> - when complete() is called:
> - if SCSI_REASON_DONE, complete client request
> - else perform the client "DMA" for "arg" bytes
> - call the device scsi_data_read()/write() again
>
No, this is exactly as I'm expecting the SCSI layer to work.
So from the light of this the patch to scsi-generic is valid.
And it really looks like papering over a bug in the lsi HBA code.
Gerd?
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
address@hidden +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)
- [Qemu-devel] [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Nicholas A. Bellinger, 2010/11/24
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Hannes Reinecke, 2010/11/24
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Nicholas A. Bellinger, 2010/11/24
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Kevin Wolf, 2010/11/24
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Hannes Reinecke, 2010/11/24
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Kevin Wolf, 2010/11/24
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Hannes Reinecke, 2010/11/24
- Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Benjamin Herrenschmidt, 2010/11/25
- Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Gerd Hoffmann, 2010/11/25
- Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Benjamin Herrenschmidt, 2010/11/25
- Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion,
Hannes Reinecke <=
- Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Benjamin Herrenschmidt, 2010/11/25
- Re: [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Gerd Hoffmann, 2010/11/25
- [Qemu-devel] Re: [PATCH] scsi-generic: bugfixes for 'SCSIRequest' conversion, Nicholas A. Bellinger, 2010/11/24