Why is AHA152X_CS !64BIT?

Why is AHA152X_CS !64BIT?

[Jiri Slaby]

Hi,

I see that the aha152x driver for pcmcia is marked as unsupported on
64bit. But I also see a patch [1] which removes the restriction based on
user's testing in bugzilla [2].

Is there a reason why it would have to be marked as !64BIT? I'm asking
because there is an opensuse user with this card who updated to 64-bit
distro and lost this driver thereafter.

[1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
[2] https://bugzilla.kernel.org/show_bug.cgi?id=14333

thanks,
-- 
js
suse labs

Re: Why is AHA152X_CS !64BIT?

[Boaz Harrosh]

On 08/23/2010 10:59 PM, Jiri Slaby wrote:
> Hi,
> 
> I see that the aha152x driver for pcmcia is marked as unsupported on
> 64bit. But I also see a patch [1] which removes the restriction based on
> user's testing in bugzilla [2].
> 
> Is there a reason why it would have to be marked as !64BIT? I'm asking
> because there is an opensuse user with this card who updated to 64-bit
> distro and lost this driver thereafter.
> 
> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
> 
> thanks,

If memory serves correctly, it might be that you need more then 4 Gbyte
of memory installed to exercise the bug, something about IO bouncing
addresses > 4G.

But don't believe me, I might be imagining things ;-)

Boaz

Re: Why is AHA152X_CS !64BIT?

[Konrad Rzeszutek Wilk]

On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote:
> On 08/23/2010 10:59 PM, Jiri Slaby wrote:
> > Hi,
> >
> > I see that the aha152x driver for pcmcia is marked as unsupported on
> > 64bit. But I also see a patch [1] which removes the restriction based on
> > user's testing in bugzilla [2].
> >
> > Is there a reason why it would have to be marked as !64BIT? I'm asking
> > because there is an opensuse user with this card who updated to 64-bit
> > distro and lost this driver thereafter.
> >
> > [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
> > [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
> >
> > thanks,
>
> If memory serves correctly, it might be that you need more then 4 Gbyte
> of memory installed to exercise the bug, something about IO bouncing
> addresses > 4G.

If the machine is using SWIOTLB, then the bounce buffer would be activated. By 
default if your machine has more than 4GB compiled under x86_64 the SWIOTLB 
is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which 
is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as 
long as the driver has pci_dma_mask_set.

Looking at the git gui blame tool history, the reason that was added was 
for 'allow drivers to be built non-modular'.

So, does this driver build if you make it non-modular?

Re: Why is AHA152X_CS !64BIT?

[Randy Dunlap]

On 09/07/10 14:12, Konrad Rzeszutek Wilk wrote:
> On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote:
>> On 08/23/2010 10:59 PM, Jiri Slaby wrote:
>>> Hi,
>>>
>>> I see that the aha152x driver for pcmcia is marked as unsupported on
>>> 64bit. But I also see a patch [1] which removes the restriction based on
>>> user's testing in bugzilla [2].
>>>
>>> Is there a reason why it would have to be marked as !64BIT? I'm asking
>>> because there is an opensuse user with this card who updated to 64-bit
>>> distro and lost this driver thereafter.
>>>
>>> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
>>> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
>>>
>>> thanks,
>>
>> If memory serves correctly, it might be that you need more then 4 Gbyte
>> of memory installed to exercise the bug, something about IO bouncing
>> addresses > 4G.
> 
> If the machine is using SWIOTLB, then the bounce buffer would be activated. By 
> default if your machine has more than 4GB compiled under x86_64 the SWIOTLB 
> is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which 
> is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as 
> long as the driver has pci_dma_mask_set.
> 
> Looking at the git gui blame tool history, the reason that was added was 
> for 'allow drivers to be built non-modular'.

023ae619 (Robert P. J. Day  2007-03-26 16:06:45 -0400 14) 	depends on !64BIT

That commit just removed the "depends on m" part:

-	depends on m && !64BIT
+	depends on !64BIT


> So, does this driver build if you make it non-modular?

It shouldn't since it still depends on !64BIT.

I expect someone thought or had evidence that the driver was not 64-bit clean.

Is the bitkeeper kernel repo still visible somewhere?
Looks like we would need to look at it for patch history that far back.

-- 
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: Why is AHA152X_CS !64BIT?

[Randy Dunlap]

On 09/07/10 14:41, Randy Dunlap wrote:
> On 09/07/10 14:12, Konrad Rzeszutek Wilk wrote:
>> On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote:
>>> On 08/23/2010 10:59 PM, Jiri Slaby wrote:
>>>> Hi,
>>>>
>>>> I see that the aha152x driver for pcmcia is marked as unsupported on
>>>> 64bit. But I also see a patch [1] which removes the restriction based on
>>>> user's testing in bugzilla [2].
>>>>
>>>> Is there a reason why it would have to be marked as !64BIT? I'm asking
>>>> because there is an opensuse user with this card who updated to 64-bit
>>>> distro and lost this driver thereafter.
>>>>
>>>> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
>>>> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
>>>>
>>>> thanks,
>>>
>>> If memory serves correctly, it might be that you need more then 4 Gbyte
>>> of memory installed to exercise the bug, something about IO bouncing
>>> addresses > 4G.
>>
>> If the machine is using SWIOTLB, then the bounce buffer would be activated. By 
>> default if your machine has more than 4GB compiled under x86_64 the SWIOTLB 
>> is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which 
>> is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as 
>> long as the driver has pci_dma_mask_set.
>>
>> Looking at the git gui blame tool history, the reason that was added was 
>> for 'allow drivers to be built non-modular'.
> 
> 023ae619 (Robert P. J. Day  2007-03-26 16:06:45 -0400 14) 	depends on !64BIT
> 
> That commit just removed the "depends on m" part:
> 
> -	depends on m && !64BIT
> +	depends on !64BIT
> 
> 
>> So, does this driver build if you make it non-modular?
> 
> It shouldn't since it still depends on !64BIT.
> 
> I expect someone thought or had evidence that the driver was not 64-bit clean.
> 
> Is the bitkeeper kernel repo still visible somewhere?
> Looks like we would need to look at it for patch history that far back.
> 

http://linux.bkbits.net:8080/linux-2.6/?PAGE=cset&REV=3fe0bc41KO89ooP68UcrHEMVVAfDnw

but it doesn't quite make sense to me.  Sure, no ISA on x86_64, but that does not
mean no PCMCIA on x86_64.

-- 
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: Why is AHA152X_CS !64BIT?

[James Bottomley]

On Tue, 2010-09-07 at 14:48 -0700, Randy Dunlap wrote:
> On 09/07/10 14:41, Randy Dunlap wrote:
> > On 09/07/10 14:12, Konrad Rzeszutek Wilk wrote:
> >> On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote:
> >>> On 08/23/2010 10:59 PM, Jiri Slaby wrote:
> >>>> Hi,
> >>>>
> >>>> I see that the aha152x driver for pcmcia is marked as unsupported on
> >>>> 64bit. But I also see a patch [1] which removes the restriction based on
> >>>> user's testing in bugzilla [2].
> >>>>
> >>>> Is there a reason why it would have to be marked as !64BIT? I'm asking
> >>>> because there is an opensuse user with this card who updated to 64-bit
> >>>> distro and lost this driver thereafter.
> >>>>
> >>>> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
> >>>> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
> >>>>
> >>>> thanks,
> >>>
> >>> If memory serves correctly, it might be that you need more then 4 Gbyte
> >>> of memory installed to exercise the bug, something about IO bouncing
> >>> addresses > 4G.
> >>
> >> If the machine is using SWIOTLB, then the bounce buffer would be activated. By 
> >> default if your machine has more than 4GB compiled under x86_64 the SWIOTLB 
> >> is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which 
> >> is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as 
> >> long as the driver has pci_dma_mask_set.
> >>
> >> Looking at the git gui blame tool history, the reason that was added was 
> >> for 'allow drivers to be built non-modular'.
> > 
> > 023ae619 (Robert P. J. Day  2007-03-26 16:06:45 -0400 14) 	depends on !64BIT
> > 
> > That commit just removed the "depends on m" part:
> > 
> > -	depends on m && !64BIT
> > +	depends on !64BIT
> > 
> > 
> >> So, does this driver build if you make it non-modular?
> > 
> > It shouldn't since it still depends on !64BIT.
> > 
> > I expect someone thought or had evidence that the driver was not 64-bit clean.
> > 
> > Is the bitkeeper kernel repo still visible somewhere?
> > Looks like we would need to look at it for patch history that far back.
> > 
> 
> http://linux.bkbits.net:8080/linux-2.6/?PAGE=cset&REV=3fe0bc41KO89ooP68UcrHEMVVAfDnw
> 
> but it doesn't quite make sense to me.  Sure, no ISA on x86_64, but that does not
> mean no PCMCIA on x86_64.

Actually, the patch is this one:

http://permalink.gmane.org/gmane.linux.scsi/5835

The complaint is that the driver spews warnings on a 64 bit compile, so
it's likely not 64 bit clean.

James

Re: Why is AHA152X_CS !64BIT?

[Jiri Slaby]

On 09/08/2010 12:10 AM, James Bottomley wrote:
> On Tue, 2010-09-07 at 14:48 -0700, Randy Dunlap wrote:
>> On 09/07/10 14:41, Randy Dunlap wrote:
>>> On 09/07/10 14:12, Konrad Rzeszutek Wilk wrote:
>>>> On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote:
>>>>> On 08/23/2010 10:59 PM, Jiri Slaby wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I see that the aha152x driver for pcmcia is marked as unsupported on
>>>>>> 64bit. But I also see a patch [1] which removes the restriction based on
>>>>>> user's testing in bugzilla [2].
>>>>>>
>>>>>> Is there a reason why it would have to be marked as !64BIT? I'm asking
>>>>>> because there is an opensuse user with this card who updated to 64-bit
>>>>>> distro and lost this driver thereafter.
>>>>>>
>>>>>> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
>>>>>> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
>>>>>>
>>>>>> thanks,
>>>>>
>>>>> If memory serves correctly, it might be that you need more then 4 Gbyte
>>>>> of memory installed to exercise the bug, something about IO bouncing
>>>>> addresses > 4G.
>>>>
>>>> If the machine is using SWIOTLB, then the bounce buffer would be activated. By 
>>>> default if your machine has more than 4GB compiled under x86_64 the SWIOTLB 
>>>> is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which 
>>>> is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as 
>>>> long as the driver has pci_dma_mask_set.
>>>>
>>>> Looking at the git gui blame tool history, the reason that was added was 
>>>> for 'allow drivers to be built non-modular'.
>>>
>>> 023ae619 (Robert P. J. Day  2007-03-26 16:06:45 -0400 14) 	depends on !64BIT
>>>
>>> That commit just removed the "depends on m" part:
>>>
>>> -	depends on m && !64BIT
>>> +	depends on !64BIT
>>>
>>>
>>>> So, does this driver build if you make it non-modular?
>>>
>>> It shouldn't since it still depends on !64BIT.
>>>
>>> I expect someone thought or had evidence that the driver was not 64-bit clean.
>>>
>>> Is the bitkeeper kernel repo still visible somewhere?
>>> Looks like we would need to look at it for patch history that far back.
>>>
>>
>> http://linux.bkbits.net:8080/linux-2.6/?PAGE=cset&REV=3fe0bc41KO89ooP68UcrHEMVVAfDnw
>>
>> but it doesn't quite make sense to me.  Sure, no ISA on x86_64, but that does not
>> mean no PCMCIA on x86_64.
> 
> Actually, the patch is this one:
> 
> http://permalink.gmane.org/gmane.linux.scsi/5835
> 
> The complaint is that the driver spews warnings on a 64 bit compile, so
> it's likely not 64 bit clean.

As I wrote few minutes ago, there is only one which is in print. And I
cannot find anybody fixing anything similar since 2.1.

So can we enable it on 64-bit when we have two reports it works on
64-bit? (Is it still maintained? MAINTAINERS says so...)

thanks,
-- 
js
suse labs

Re: Why is AHA152X_CS !64BIT?

[=?unknown-8bit?B?SvxyZ2VuIEUu?= Fischer]

Hi Jiri,

On Wed, Sep 08, 2010 at 00:16:06 +0200, Jiri Slaby wrote:
> As I wrote few minutes ago, there is only one which is in print. And I
> cannot find anybody fixing anything similar since 2.1.
 
> So can we enable it on 64-bit when we have two reports it works on
> 64-bit? (Is it still maintained? MAINTAINERS says so...)

For the maintainance: My ISA machine is defunct, but I still have a
PCMCIA card to test and debug it needed - although no 64bit machine with
a PCMCIA slot.

I suppose the hardware is so hardly used nowadays, that there simply
hasn't been any need for aha152x specific changes (or debugging) for
years.  And all the interface updates were done by whoever changed the
generic interface and I eventually ceased to follow.

So I guess the maintainance state should be changed to "Odd fixes" at
best.


Juergen

Re: Why is AHA152X_CS !64BIT?

[Jiri Slaby]

On 09/07/2010 11:48 PM, Randy Dunlap wrote:
> On 09/07/10 14:41, Randy Dunlap wrote:
>> On 09/07/10 14:12, Konrad Rzeszutek Wilk wrote:
>>> On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote:
>>>> On 08/23/2010 10:59 PM, Jiri Slaby wrote:
>>>>> Hi,
>>>>>
>>>>> I see that the aha152x driver for pcmcia is marked as unsupported on
>>>>> 64bit. But I also see a patch [1] which removes the restriction based on
>>>>> user's testing in bugzilla [2].
>>>>>
>>>>> Is there a reason why it would have to be marked as !64BIT? I'm asking
>>>>> because there is an opensuse user with this card who updated to 64-bit
>>>>> distro and lost this driver thereafter.
>>>>>
>>>>> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393
>>>>> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333
>>>>>
>>>>> thanks,
>>>>
>>>> If memory serves correctly, it might be that you need more then 4 Gbyte
>>>> of memory installed to exercise the bug, something about IO bouncing
>>>> addresses > 4G.
>>>
>>> If the machine is using SWIOTLB, then the bounce buffer would be activated. By 
>>> default if your machine has more than 4GB compiled under x86_64 the SWIOTLB 
>>> is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which 
>>> is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as 
>>> long as the driver has pci_dma_mask_set.
>>>
>>> Looking at the git gui blame tool history, the reason that was added was 
>>> for 'allow drivers to be built non-modular'.
>>
>> 023ae619 (Robert P. J. Day  2007-03-26 16:06:45 -0400 14) 	depends on !64BIT
>>
>> That commit just removed the "depends on m" part:
>>
>> -	depends on m && !64BIT
>> +	depends on !64BIT
>>
>>
>>> So, does this driver build if you make it non-modular?
>>
>> It shouldn't since it still depends on !64BIT.
>>
>> I expect someone thought or had evidence that the driver was not 64-bit clean.
>>
>> Is the bitkeeper kernel repo still visible somewhere?
>> Looks like we would need to look at it for patch history that far back.
>>
> 
> http://linux.bkbits.net:8080/linux-2.6/?PAGE=cset&REV=3fe0bc41KO89ooP68UcrHEMVVAfDnw
> 
> but it doesn't quite make sense to me.  Sure, no ISA on x86_64, but that does not
> mean no PCMCIA on x86_64.

Hmm, the changelog says:
The warning I saw was actually for the PCMCIA aha152x driver.

which I think are compiler warnings. But I see only one emitted by the
compiler and it is in a debug print.

thanks,
-- 
js
suse labs

Re: Why is AHA152X_CS !64BIT?

[Andi Kleen]

> 
> Hmm, the changelog says:
> The warning I saw was actually for the PCMCIA aha152x driver.
> 
> which I think are compiler warnings. But I see only one emitted by the
> compiler and it is in a debug print.


Don't remember the exact warning, but I was rather trigger happy
on getting rid of all these ancient unmaintained drivers on 64bit 
back then.

In hindsight it was the right thing to do -- their userbase
seems to be near zero and there were little to no complains 
about it ever.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

Re: Why is AHA152X_CS !64BIT?

[James Bottomley]

On Wed, 2010-09-08 at 08:05 +0200, Andi Kleen wrote:
> > 
> > Hmm, the changelog says:
> > The warning I saw was actually for the PCMCIA aha152x driver.
> > 
> > which I think are compiler warnings. But I see only one emitted by the
> > compiler and it is in a debug print.
> 
> 
> Don't remember the exact warning, but I was rather trigger happy
> on getting rid of all these ancient unmaintained drivers on 64bit 
> back then.
> 
> In hindsight it was the right thing to do -- their userbase
> seems to be near zero and there were little to no complains 
> about it ever.

OK ... let's try it.  Jiří send a patch ... and if it breaks I'm handing
you the pieces ...

James


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Re: Why is AHA152X_CS !64BIT?

[Andi Kleen]

> OK ... let's try it.  Jiří send a patch ... and if it breaks I'm
> handing you the pieces ...

You mean reenable it? Why? Do you have any indication the user base
of this thing (especially on 64bit) is > 0? 

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.
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Re: Why is AHA152X_CS !64BIT?

[Jiri Slaby]

On 09/09/2010 09:50 AM, Andi Kleen wrote:
>> OK ... let's try it.  Jiří send a patch ... and if it breaks I'm
>> handing you the pieces ...
> 
> You mean reenable it? Why? Do you have any indication the user base
> of this thing (especially on 64bit) is > 0? 

Yeah, I know of two people who upgraded to 64-bit recently and had been
using that driver before (the one for scanner). They both report it's
working if non-64bit condition is removed. So I will post a patch to
enable it back again...

regards,
-- 
js
suse labs
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