[ofw] RE: Bad merge in checking 1440

[Fab Tillier]

> From: Sean Hefty [mailto:sean.hefty at intel.com]
> Sent: Wednesday, July 23, 2008 4:01 PM
>
>> UAL_POST_SEND and UAL_POST_RECV IOCTLs, issued from ual_post_send and
>> ual_post_recv functions in core\al\user\ual_qp.c
>>
>> The ib_wc_t structure is passed in the UAL_POLL_CQ IOCTL issued in
>> core\al\user\ual_cq.c
>
> Yes - I can see this code, but how do you invoke it?

Delete mthcau.dll and/or mthcaud.dll, and then run something over WSD or some other client.

A failure in loading the UVP DLL will also cause things to fall back to the IOCTL interface since open_vendor_lib doesn't return an error if things don't work.

>> I don't have issue with the code as part of a larger change, just not
>> on its own like this.  As it stands you reintroduced a bug in there for
>> someone to trip over.  The purpose of the IOCTL-driven WR and CQ
>> processing is to facilitate new HCA drivers being developed.  A
>> functional kernel driver was intended to be able to fully support
>> user-mode clients, though at a performance loss.
>>
>> So either keep the existing functionality (and fix the IOCTL handling),
>> or delete it.  Don't break the IOCTL handling but leave the
>> functionality in there.  It probably makes sense to have a discussion
>> about removing the WR and CQ IOCTL support before yanking it, though I
>> don't foresee any issues.
>  The code that's there should work for 32-bit apps on 32-bit kernels,
> and 64-bit apps on 64-bit kernels.  I can add code to make it 'work' for
> 32-bit apps on a 64-bit kernel, but nothing will still use it...  Is it
> really worth the effort?

When someone enables WSD on a 64-bit OS they get both the 32-bit and 64-bit DLLs installed.  If a failure to load the UVP is encountered you could end up with a problem.

I'd probably just delete the code myself.  WinVerbs expects a UVP always, yeah?  I think that's probably a reasonable model - supporting fail back to IOCTLs adds a lot of complexity, and is unlikely to be properly tested.

-Fab