[KJ] Replacing check_region with request_region

[KJ] Replacing check_region with request_region

[Vignesh Babu BM]

Hi,
  I found the following instances of check_region in the 2.6.20-rc5
code.
  I also found that these files also have request_region in some parts.
So I was just wondering if they were left there for some reason....but
as part of the deprecated API they have to be removed at some point of
time right?
  If they need to be changed then I would go ahead and make a patch.
Thanks...

drivers/cdrom/sbpcd.c

                if (check_region(addr[1],4))
                {
                        msg(DBG_INF,"check_region: %03X is not
free.\n",addr[1]);
                        continue;
                }
------------------------------------------------------------------
drivers/scsi/BusLogic.c

        /*
           Append the list of standard BusLogic MultiMaster ISA I/O
Addresses.
         */
        if (BusLogic_ProbeOptions.LimitedProbeISA ?
BusLogic_ProbeOptions.Probe330 : check_region(0x330,
BusLogic_MultiMasterAddressCount) = 0)
                BusLogic_AppendProbeAddressISA(0x330);
        if (BusLogic_ProbeOptions.LimitedProbeISA ?
BusLogic_ProbeOptions.Probe334 : check_region(0x334,
BusLogic_MultiMasterAddressCount) = 0)
                BusLogic_AppendProbeAddressISA(0x334);
        if (BusLogic_ProbeOptions.LimitedProbeISA ?
BusLogic_ProbeOptions.Probe230 : check_region(0x230,
BusLogic_MultiMasterAddressCount) = 0)
                BusLogic_AppendProbeAddressISA(0x230);
        if (BusLogic_ProbeOptions.LimitedProbeISA ?
BusLogic_ProbeOptions.Probe234 : check_region(0x234,
BusLogic_MultiMasterAddressCount) = 0)
                BusLogic_AppendProbeAddressISA(0x234);
        if (BusLogic_ProbeOptions.LimitedProbeISA ?
BusLogic_ProbeOptions.Probe130 : check_region(0x130,
BusLogic_MultiMasterAddressCount) = 0)
                BusLogic_AppendProbeAddressISA(0x130);
        if (BusLogic_ProbeOptions.LimitedProbeISA ?
BusLogic_ProbeOptions.Probe134 : check_region(0x134,
BusLogic_MultiMasterAddressCount) = 0)
                BusLogic_AppendProbeAddressISA(0x134);
----------------------------------------------------------------
drivers/scsi/advansys.c

                        if (check_region(iop, ASC_IOADR_GAP) != 0) {
                            printk(
"AdvanSys SCSI: specified I/O Port 0x%X is busy\n", iop);
-----------------------------------------------------------------
sound/oss/pss.c

        else if(check_region(pss_cdrom_port, 2))
        {
                printk(KERN_ERR "PSS: CDROM I/O port conflict.\n");
        }
-----------------------------------------------------------------
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Re: [KJ] Replacing check_region with request_region

[Ahmed S. Darwish]

On Mon, Jan 22, 2007 at 08:15:26PM +0530, Vignesh Babu BM wrote:
> Hi,
>   I found the following instances of check_region in the 2.6.20-rc5
> code.
>   I also found that these files also have request_region in some parts.
> So I was just wondering if they were left there for some reason....but
> as part of the deprecated API they have to be removed at some point of
> time right?
>   If they need to be changed then I would go ahead and make a patch.
> Thanks...

From LDD3, Chapter 9:
"Here, the return value is a negative error code if the given ports are not 
available. This function is deprecated because its return value provides no
guarantee of whether an allocation would succeed; checking and later
allocating are not an atomic operation"

I think they should ..

-- 
Ahmed S. Darwish
http://darwish-07.blogspot.com
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Re: [KJ] Replacing check_region with request_region

[Jesper Juhl]

On 22/01/07, Vignesh Babu BM <vignesh.babu@wipro.com> wrote:
> Hi,
>   I found the following instances of check_region in the 2.6.20-rc5
> code.
>   I also found that these files also have request_region in some parts.
> So I was just wondering if they were left there for some reason....but
> as part of the deprecated API they have to be removed at some point of
> time right?
>   If they need to be changed then I would go ahead and make a patch.
> Thanks...
>
Yes, check region needs to go away. But there is no rush, most of the
remaining users are in rarely used drivers and are usually used in
ways where the problematic race is very unlikely.

Just be sure you handle errors and properly release regions when the
driver is done with them etc...

-- 
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html
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