From: Gene Heskett <gene.heskett@verizon.net>
Reply-To: gene.heskett@verizon.net
Organization: None that appears to be detectable by casual observers
To: "Randy.Dunlap" <rddunlap@osdl.org>
Subject: Re: 2.4 vs 2.6 versions of include/linux/ioport.h
Date: Tue, 5 Aug 2003 15:08:19 -0400
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On Tuesday 05 August 2003 11:45, Randy.Dunlap wrote:
>On Tue, 5 Aug 2003 11:22:35 -0400 Gene Heskett 
<gene.heskett@verizon.net> wrote:
>| On Tuesday 05 August 2003 10:57, Randy.Dunlap wrote:
>| >On Tue, 5 Aug 2003 10:41:08 -0400 Gene Heskett
>|
>| <gene.heskett@verizon.net> wrote:
>| >| ----
>| >| First, the define itself is missing in the 2.6 version.
>| >|
>| >| Many drivers seem to use this call, and in that which I'm
>| >| trying to build, the nforce and advansys modules use it.  And
>| >| while the modules seem to build, they do not run properly.
>| >|
>| >| I cannot run 2.6.x for extended tests because of the advansys
>| >| breakage this causes.  I also haven't even tried to run X
>| >| because of the nforce error reported when its built, the same
>| >| error as attacks the advansys code.
>| >|
>| >| Can I ask why this change was made, and is there a suitable
>| >| replacement call available that these drivers could use instead
>| >| of check_region(), as shown here in a snip from advansys.c?
>| >| ----
>| >| if (check_region(iop, ASC_IOADR_GAP) != 0) {
>| >| ...
>| >| if (check_region(iop_base, ASC_IOADR_GAP) != 0) {
>| >| ...
>| >|
>| >| Hopeing for some hints here.
>| >
>| >check_region() was racy.  Use request_region() instead.
>| >
>| >   if (!request_region(iop, ASC_IOADR_GAP, "advansys")) {
>| >   ...
>| >
>| >   if (!request_region(iop_base, ASC_IOADR, "advansys")) {
>| >   ...
>| >
>| >Of course, if successful, this assigns the region to the driver,
>| >while check_region() didn't do this, so release_region() should
>| > be used as needed to return the resources.
>|
>| Oops... I have a test compile going that changed those to
>| check_mem_region.  And while I didn't change the i2c stuff, which
>| still reports the error, advansys.o built w/o error this time.
>|
>| Ok, so I can change that to !request_region, but I have NDI when
>| to go about releasing it, if ever, for a kernel driver thats
>| either there, and the hardware is used, or not because the
>| hardware isn't present.
>
>release_region() is already done for the normal case.
>It needs to be added for the error cases in advansys_detect()
>[wow, what a long function].
>For your kernel(s) and known hardware, it may not be much of an
>issue.  However, the in-kernel driver needs to be repaired, but
>it seems that not many people have the hardware...
>
>| It seems to me that if its allocated to this driver, and capable
>| of being re-used at anytime, then the allocation should, once
>| made, stand.
>
>Yes, request_region() should keep the region assigned until the
> driver is exiting (unloading).  release_region() is already done in
> advansys_release().
>
>| Or is my view of the world skewed and it should be done at
>| the bottom of whatever conditional is involved?  Inquiring minds
>| want to know.  I guess it all depends on what happens if the call
>| is repeated.  Will it assign a new buffer each time?, thereby
>| causeing a memory leak, or will it find its been done once and
>| return success anyway?
>
>advansys_detect() should call release_region() if it encounters
> errors [after it has called request_region() and returns an error].
>
>request_region() doesn't assign buffers, it allocates IO resources,
>as seen in /proc/ioports or /proc/iomem.  I don't know what happens
>on repeated calls by the same driver|module, but in general a second
>call will fail if the region is already allocated.
>
>--
>~Randy

All that code is loosely bundled under the heading of advansys_init, 
and from the useage of a header constant in the code to control the 
"for (i = CONSTANT" loop above it, would appear to be looped 11 
times.  Thats not the correct syntax of course, but you get the idea 
I hope.

I've built it that way now, without any errors, so its time to go fire 
up a weed eater acording to the missus, and I'll do a test reboot 
later tonight just for any grins it might generate.  I also took all 
the i2c stuff out, and might try building that once I'm rebooted, but 
I think a name change was made from "modversions" in the 
lib/modules/version tree, so that will probably fail until I fix the 
&^%$@() makefile.

I'll let you know how it goes later.  Many thanks for the help, I 
figured I was dead and would have to go buy a (spit) adaptec card.

-- 
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz  512M
99.27% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attornies please note, additions to this message
by Gene Heskett are:
Copyright 2003 by Maurice Eugene Heskett, all rights reserved.

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