[patch 3/3] ata: SWNCQ should be enabled by default

[patch 3/3] ata: SWNCQ should be enabled by default

[akpm]

From: Zoltan Boszormenyi <zboszor@dunaweb.hu>

unchangelogged patch.

Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/ata/sata_nv.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN drivers/ata/sata_nv.c~ata-swncq-should-be-enabled-by-default drivers/ata/sata_nv.c
--- a/drivers/ata/sata_nv.c~ata-swncq-should-be-enabled-by-default
+++ a/drivers/ata/sata_nv.c
@@ -532,7 +532,7 @@ MODULE_DEVICE_TABLE(pci, nv_pci_tbl);
 MODULE_VERSION(DRV_VERSION);
 
 static int adma_enabled = 1;
-static int swncq_enabled;
+static int swncq_enabled = 1;
 
 static void nv_adma_register_mode(struct ata_port *ap)
 {
@@ -2485,5 +2485,5 @@ module_exit(nv_exit);
 module_param_named(adma, adma_enabled, bool, 0444);
 MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: true)");
 module_param_named(swncq, swncq_enabled, bool, 0444);
-MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: false)");
+MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: true)");
 
_

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Tejun Heo]

akpm@linux-foundation.org wrote:
> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
> 
> unchangelogged patch.
> 
> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
> Cc: Robert Hancock <hancockr@shaw.ca>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Nacked-by: Tejun Heo <htejun@gmail.com>

Sorry, there are remaining issues to resolve before enabling ADMA by 
default.

-- 
tejun

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Zoltan Boszormenyi]

Tejun Heo írta:
> akpm@linux-foundation.org wrote:
>> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>
>> unchangelogged patch.
>>
>> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>> Cc: Robert Hancock <hancockr@shaw.ca>
>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>
> Nacked-by: Tejun Heo <htejun@gmail.com>
>
> Sorry, there are remaining issues to resolve before enabling ADMA by 
> default.

Sorry, this is NOT ADMA. SWNCQ is completely independent from ADMA.

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Tejun Heo]

Zoltan Boszormenyi wrote:
> Tejun Heo írta:
>> akpm@linux-foundation.org wrote:
>>> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>
>>> unchangelogged patch.
>>>
>>> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>> Cc: Robert Hancock <hancockr@shaw.ca>
>>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>>
>> Nacked-by: Tejun Heo <htejun@gmail.com>
>>
>> Sorry, there are remaining issues to resolve before enabling ADMA by 
>> default.
> 
> Sorry, this is NOT ADMA. SWNCQ is completely independent from ADMA.

Heh, right.  Sorry about that.  I disabled ADMA on the distro I work for 
and somehow ADMA was disabled on mainline too.  :-)

Robert, is SWNCQ safe to turn on by default?  I personally think it's 
better to prefer safety over performance or optional features and given 
the history of NCQ support on nv satas, I feel a bit more cautious.

Maybe we can enable SWNCQ on -mm and devel branches and disable it late 
in release cycle for 2.6.26 for a trial?

Kuan Luo and Peer Chen, what do you guys think about this?  And can you 
guys please find a way to assist Robert in fixing the ADMA problems? 
For 2.6.25, we're too late to disable it.  For 2.6.26, I'm afraid we 
will have to disable it unless those known issues are solved.  :-(

Thanks.

-- 
tejun

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Robert Hancock]

Tejun Heo wrote:
> Zoltan Boszormenyi wrote:
>> Tejun Heo írta:
>>> akpm@linux-foundation.org wrote:
>>>> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>>
>>>> unchangelogged patch.
>>>>
>>>> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>> Cc: Robert Hancock <hancockr@shaw.ca>
>>>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>>>
>>> Nacked-by: Tejun Heo <htejun@gmail.com>
>>>
>>> Sorry, there are remaining issues to resolve before enabling ADMA by 
>>> default.
>>
>> Sorry, this is NOT ADMA. SWNCQ is completely independent from ADMA.
> 
> Heh, right.  Sorry about that.  I disabled ADMA on the distro I work for 
> and somehow ADMA was disabled on mainline too.  :-)
> 
> Robert, is SWNCQ safe to turn on by default?  I personally think it's 
> better to prefer safety over performance or optional features and given 
> the history of NCQ support on nv satas, I feel a bit more cautious.
> 
> Maybe we can enable SWNCQ on -mm and devel branches and disable it late 
> in release cycle for 2.6.26 for a trial?

I haven't seen any problem reports, but with it disabled by default most 
people haven't tried it. The only way to really know is to try turning 
it on by default and see what shakes out.

I'd vote to enable it by default in -mm and 2.6.26-rc and see what happens.

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Tejun Heo]

Robert Hancock wrote:
> Tejun Heo wrote:
>> Zoltan Boszormenyi wrote:
>>> Tejun Heo írta:
>>>> akpm@linux-foundation.org wrote:
>>>>> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>>>
>>>>> unchangelogged patch.
>>>>>
>>>>> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>>> Cc: Robert Hancock <hancockr@shaw.ca>
>>>>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>>>>
>>>> Nacked-by: Tejun Heo <htejun@gmail.com>
>>>>
>>>> Sorry, there are remaining issues to resolve before enabling ADMA by 
>>>> default.
>>>
>>> Sorry, this is NOT ADMA. SWNCQ is completely independent from ADMA.
>>
>> Heh, right.  Sorry about that.  I disabled ADMA on the distro I work 
>> for and somehow ADMA was disabled on mainline too.  :-)
>>
>> Robert, is SWNCQ safe to turn on by default?  I personally think it's 
>> better to prefer safety over performance or optional features and 
>> given the history of NCQ support on nv satas, I feel a bit more cautious.
>>
>> Maybe we can enable SWNCQ on -mm and devel branches and disable it 
>> late in release cycle for 2.6.26 for a trial?
> 
> I haven't seen any problem reports, but with it disabled by default most 
> people haven't tried it. The only way to really know is to try turning 
> it on by default and see what shakes out.
> 
> I'd vote to enable it by default in -mm and 2.6.26-rc and see what happens.

Alright, Zoltan can you please repost w/ commit message fixed and 
comment stating /* FIXME: for testing during blah blah */ added?

-- 
tejun

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Zoltan Boszormenyi]

[-- Attachment #1: Type: text/plain, Size: 1634 bytes --]

Tejun Heo írta:
> Robert Hancock wrote:
>> Tejun Heo wrote:
>>> Zoltan Boszormenyi wrote:
>>>> Tejun Heo írta:
>>>>> akpm@linux-foundation.org wrote:
>>>>>> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>>>>
>>>>>> unchangelogged patch.
>>>>>>
>>>>>> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>>>> Cc: Robert Hancock <hancockr@shaw.ca>
>>>>>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>>>>>
>>>>> Nacked-by: Tejun Heo <htejun@gmail.com>
>>>>>
>>>>> Sorry, there are remaining issues to resolve before enabling ADMA 
>>>>> by default.
>>>>
>>>> Sorry, this is NOT ADMA. SWNCQ is completely independent from ADMA.
>>>
>>> Heh, right.  Sorry about that.  I disabled ADMA on the distro I work 
>>> for and somehow ADMA was disabled on mainline too.  :-)
>>>
>>> Robert, is SWNCQ safe to turn on by default?  I personally think 
>>> it's better to prefer safety over performance or optional features 
>>> and given the history of NCQ support on nv satas, I feel a bit more 
>>> cautious.
>>>
>>> Maybe we can enable SWNCQ on -mm and devel branches and disable it 
>>> late in release cycle for 2.6.26 for a trial?
>>
>> I haven't seen any problem reports, but with it disabled by default 
>> most people haven't tried it. The only way to really know is to try 
>> turning it on by default and see what shakes out.
>>
>> I'd vote to enable it by default in -mm and 2.6.26-rc and see what 
>> happens.
>
> Alright, Zoltan can you please repost w/ commit message fixed and 
> comment stating /* FIXME: for testing during blah blah */ added?
>

You mean like this?


[-- Attachment #2: sata_nv-swncq_enabled-1.patch --]
[-- Type: text/x-patch, Size: 1125 bytes --]

Enable SWNCQ by default for testing in 2.6.26-rcX[-mm] and 

Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/ata/sata_nv.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN drivers/ata/sata_nv.c~ata-swncq-should-be-enabled-by-default drivers/ata/sata_nv.c
--- a/drivers/ata/sata_nv.c~ata-swncq-should-be-enabled-by-default
+++ a/drivers/ata/sata_nv.c
@@ -532,7 +532,7 @@ MODULE_DEVICE_TABLE(pci, nv_pci_tbl);
 MODULE_VERSION(DRV_VERSION);
 
 static int adma_enabled = 1;
-static int swncq_enabled;
+static int swncq_enabled = 1;	/* FIXME: for testing during 2.6.26-rcX[-mmY] */
 
 static void nv_adma_register_mode(struct ata_port *ap)
 {
@@ -2485,5 +2485,5 @@ module_exit(nv_exit);
 module_param_named(adma, adma_enabled, bool, 0444);
 MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: true)");
 module_param_named(swncq, swncq_enabled, bool, 0444);
-MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: false)");
+MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: true)");
 

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Tejun Heo]

Zoltan Boszormenyi wrote:
>> Alright, Zoltan can you please repost w/ commit message fixed and 
>> comment stating /* FIXME: for testing during blah blah */ added?
>>
> 
> You mean like this?

Yeap, Acked-by: Tejun Heo <htejun@gmail.com>

-- 
tejun

RE: [patch 3/3] ata: SWNCQ should be enabled by default

[Kuan Luo]

For ADMA, I lean to disable it for default because stability is more important to our customers. At least, bug in this link: http://www.gossamer-threads.com/lists/linux/kernel/885929  is not resolved.

Best regards,
Kuan Luo
 

> -----Original Message-----
> From: Tejun Heo [mailto:htejun@gmail.com] 
> Sent: Sunday, March 30, 2008 8:12 AM
> To: Zoltan Boszormenyi
> Cc: akpm@linux-foundation.org; jeff@garzik.org; 
> linux-ide@vger.kernel.org; hancockr@shaw.ca; Kuan Luo; Peer Chen
> Subject: Re: [patch 3/3] ata: SWNCQ should be enabled by default
> 
> Zoltan Boszormenyi wrote:
> > Tejun Heo írta:
> >> akpm@linux-foundation.org wrote:
> >>> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
> >>>
> >>> unchangelogged patch.
> >>>
> >>> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
> >>> Cc: Robert Hancock <hancockr@shaw.ca>
> >>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> >>
> >> Nacked-by: Tejun Heo <htejun@gmail.com>
> >>
> >> Sorry, there are remaining issues to resolve before 
> enabling ADMA by 
> >> default.
> > 
> > Sorry, this is NOT ADMA. SWNCQ is completely independent from ADMA.
> 
> Heh, right.  Sorry about that.  I disabled ADMA on the distro 
> I work for 
> and somehow ADMA was disabled on mainline too.  :-)
> 
> Robert, is SWNCQ safe to turn on by default?  I personally think it's 
> better to prefer safety over performance or optional features 
> and given 
> the history of NCQ support on nv satas, I feel a bit more cautious.
> 
> Maybe we can enable SWNCQ on -mm and devel branches and 
> disable it late 
> in release cycle for 2.6.26 for a trial?
> 
> Kuan Luo and Peer Chen, what do you guys think about this?  
> And can you 
> guys please find a way to assist Robert in fixing the ADMA problems? 
> For 2.6.25, we're too late to disable it.  For 2.6.26, I'm afraid we 
> will have to disable it unless those known issues are solved.  :-(
> 
> Thanks.
> 
> -- 
> tejun
> 
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Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Tejun Heo]

Kuan Luo wrote:
> For ADMA, I lean to disable it for default because stability is more
> important to our customers. At least, bug in this link:
> http://www.gossamer-threads.com/lists/linux/kernel/885929  is not
> resolved.

Robert, what do you think?  Should we disable ADMA by default from 
2.6.26-rcX?

-- 
tejun

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Robert Hancock]

Tejun Heo wrote:
> Kuan Luo wrote:
>> For ADMA, I lean to disable it for default because stability is more
>> important to our customers. At least, bug in this link:
>> http://www.gossamer-threads.com/lists/linux/kernel/885929  is not
>> resolved.
> 
> Robert, what do you think?  Should we disable ADMA by default from 
> 2.6.26-rcX?
> 

I can't say I'm inherently in favor of it, but if people feel strongly 
enough about it I won't yell too loudly. If we do disable it, I would 
suggest printing out a message saying it can be enabled when the driver 
loads if they didn't switch it on, in case people complain about it as a 
regression otherwise.

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Robert Hancock]

Robert Hancock wrote:
> Tejun Heo wrote:
>> Kuan Luo wrote:
>>> For ADMA, I lean to disable it for default because stability is more
>>> important to our customers. At least, bug in this link:
>>> http://www.gossamer-threads.com/lists/linux/kernel/885929  is not
>>> resolved.
>>
>> Robert, what do you think?  Should we disable ADMA by default from 
>> 2.6.26-rcX?
>>
> 
> I can't say I'm inherently in favor of it, but if people feel strongly 
> enough about it I won't yell too loudly. If we do disable it, I would 
> suggest printing out a message saying it can be enabled when the driver 
> loads if they didn't switch it on, in case people complain about it as a 
> regression otherwise.

BTW, it would be nice if NVIDIA would put some more resources into 
debugging these issues so that we didn't have to take such an action. 
With some of these problems, there are definite limits to what we can do 
to figure out what's going on without knowing what is happening 
internally in the controller.

By my reckoning the known issues are:

-Occasional timeouts when issuing the first command after switching from 
NCQ to non-NCQ commands (even with the udelay() call in the driver to 
partially work around this). When this happens, going into register mode 
during error handling times out.

-When handling a failed command (ex: caused by a bad sector), going into 
register mode times out and retrieving result taskfile from ATA 
registers can cause a MCE due to a northbridge HyperTransport bus 
transaction timeout (reported by Kuan, I don't think anyone else has 
mentioned this one).

-Hotplug/hot-unplug fails to work properly, hotplug interrupts not 
raised (seemingly only on certain boards/configurations as I can't 
duplicate this problem). http://bugzilla.kernel.org/show_bug.cgi?id=8421

RE: [patch 3/3] ata: SWNCQ should be enabled by default

[Kuan Luo]

Robert wrote:
> -Hotplug/hot-unplug fails to work properly, hotplug interrupts not 
> raised (seemingly only on certain boards/configurations as I can't 
> duplicate this problem). 
> http://bugzilla.kernel.org/show_bug.cgi?id=8421
> 
I occasionly encountered this problem in one port under certain system,
but didn't see this issue under other systems in the same mainboard.
After adding the operation of manually clearing the added/removed
interrupt bit in NV_INT_STATUS_CK804 register 
in nv_adma_interrupt function,  i saw some improvement.  

The key problem is that no one who knows this controller comes to help
to solve these issue.
Given this disadvantage, i think disabling it maybe is a good choice.
I don't know whether we need to continue to provide patch for adma after
disabling adma function.
 
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information.  Any unauthorized review, use, disclosure or distribution
is prohibited.  If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
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Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Jeff Garzik]

Kuan Luo wrote:
> Robert wrote:
>> -Hotplug/hot-unplug fails to work properly, hotplug interrupts not 
>> raised (seemingly only on certain boards/configurations as I can't 
>> duplicate this problem). 
>> http://bugzilla.kernel.org/show_bug.cgi?id=8421
>>
> I occasionly encountered this problem in one port under certain system,
> but didn't see this issue under other systems in the same mainboard.
> After adding the operation of manually clearing the added/removed
> interrupt bit in NV_INT_STATUS_CK804 register 
> in nv_adma_interrupt function,  i saw some improvement.  
> 
> The key problem is that no one who knows this controller comes to help
> to solve these issue.
> Given this disadvantage, i think disabling it maybe is a good choice.
> I don't know whether we need to continue to provide patch for adma after
> disabling adma function.

Based on all these discussions and experiences, I just checked in the 
following commit, setting adma_enabled to zero:


     [libata] sata_nv: disable ADMA by default

     Continues to have open issues, and engineering support is extremely
	 difficult to come by, according to fellow NVIDIA engineers.

     Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Jeff Garzik]

akpm@linux-foundation.org wrote:
> From: Zoltan Boszormenyi <zboszor@dunaweb.hu>
> 
> unchangelogged patch.
> 
> Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
> Cc: Robert Hancock <hancockr@shaw.ca>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  drivers/ata/sata_nv.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff -puN drivers/ata/sata_nv.c~ata-swncq-should-be-enabled-by-default drivers/ata/sata_nv.c
> --- a/drivers/ata/sata_nv.c~ata-swncq-should-be-enabled-by-default
> +++ a/drivers/ata/sata_nv.c
> @@ -532,7 +532,7 @@ MODULE_DEVICE_TABLE(pci, nv_pci_tbl);
>  MODULE_VERSION(DRV_VERSION);
>  
>  static int adma_enabled = 1;
> -static int swncq_enabled;
> +static int swncq_enabled = 1;
>  
>  static void nv_adma_register_mode(struct ata_port *ap)
>  {
> @@ -2485,5 +2485,5 @@ module_exit(nv_exit);
>  module_param_named(adma, adma_enabled, bool, 0444);
>  MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: true)");
>  module_param_named(swncq, swncq_enabled, bool, 0444);
> -MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: false)");
> +MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: true)");

applied... we'll see how testing goes

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Jeff Garzik]

Kuan Luo wrote:
> Robert wrote:
>> -Hotplug/hot-unplug fails to work properly, hotplug interrupts not 
>> raised (seemingly only on certain boards/configurations as I can't 
>> duplicate this problem). 
>> http://bugzilla.kernel.org/show_bug.cgi?id=8421
>>
> I occasionly encountered this problem in one port under certain system,
> but didn't see this issue under other systems in the same mainboard.
> After adding the operation of manually clearing the added/removed
> interrupt bit in NV_INT_STATUS_CK804 register 
> in nv_adma_interrupt function,  i saw some improvement.  
> 
> The key problem is that no one who knows this controller comes to help
> to solve these issue.
> Given this disadvantage, i think disabling it maybe is a good choice.
> I don't know whether we need to continue to provide patch for adma after
> disabling adma function.

Is there any hope of getting permission for me to (a) give the NV ADMA 
documentation to Robert, or (b) posting the ADMA PDF on 
http://gkernel.sourceforge.net/specs/ ?

I strongly encourage vendors -- especially with chips at or past 
end-of-life -- to help customers and developers by permitting posting at 
http://gkernel.sourceforge.net/specs/

Thanks,

	Jeff

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Robert Hancock]

Jeff Garzik wrote:
> Kuan Luo wrote:
>> Robert wrote:
>>> -Hotplug/hot-unplug fails to work properly, hotplug interrupts not 
>>> raised (seemingly only on certain boards/configurations as I can't 
>>> duplicate this problem). http://bugzilla.kernel.org/show_bug.cgi?id=8421
>>>
>> I occasionly encountered this problem in one port under certain system,
>> but didn't see this issue under other systems in the same mainboard.
>> After adding the operation of manually clearing the added/removed
>> interrupt bit in NV_INT_STATUS_CK804 register in nv_adma_interrupt 
>> function,  i saw some improvement. 
>> The key problem is that no one who knows this controller comes to help
>> to solve these issue.
>> Given this disadvantage, i think disabling it maybe is a good choice.
>> I don't know whether we need to continue to provide patch for adma after
>> disabling adma function.
> 
> Is there any hope of getting permission for me to (a) give the NV ADMA 
> documentation to Robert, or (b) posting the ADMA PDF on 
> http://gkernel.sourceforge.net/specs/ ?
> 
> I strongly encourage vendors -- especially with chips at or past 
> end-of-life -- to help customers and developers by permitting posting at 
> http://gkernel.sourceforge.net/specs/
> 
> Thanks,
> 
>     Jeff

I would second that call. It's been suggested that 3rd party IP was what 
inhibited this, I don't know if that is the case or not. But it would be 
a very nice gesture if NVIDIA would do what it takes to make this possible.

Re: [patch 3/3] ata: SWNCQ should be enabled by default

[Tejun Heo]

Robert Hancock wrote:
> Jeff Garzik wrote:
>> Kuan Luo wrote:
>>> Robert wrote:
>>>> -Hotplug/hot-unplug fails to work properly, hotplug interrupts not 
>>>> raised (seemingly only on certain boards/configurations as I can't 
>>>> duplicate this problem). 
>>>> http://bugzilla.kernel.org/show_bug.cgi?id=8421
>>>>
>>> I occasionly encountered this problem in one port under certain system,
>>> but didn't see this issue under other systems in the same mainboard.
>>> After adding the operation of manually clearing the added/removed
>>> interrupt bit in NV_INT_STATUS_CK804 register in nv_adma_interrupt 
>>> function,  i saw some improvement. The key problem is that no one who 
>>> knows this controller comes to help
>>> to solve these issue.
>>> Given this disadvantage, i think disabling it maybe is a good choice.
>>> I don't know whether we need to continue to provide patch for adma after
>>> disabling adma function.
>>
>> Is there any hope of getting permission for me to (a) give the NV ADMA 
>> documentation to Robert, or (b) posting the ADMA PDF on 
>> http://gkernel.sourceforge.net/specs/ ?
>>
>> I strongly encourage vendors -- especially with chips at or past 
>> end-of-life -- to help customers and developers by permitting posting 
>> at http://gkernel.sourceforge.net/specs/
>>
>> Thanks,
>>
>>     Jeff
> 
> I would second that call. It's been suggested that 3rd party IP was what 
> inhibited this, I don't know if that is the case or not. But it would be 
> a very nice gesture if NVIDIA would do what it takes to make this possible.

/me thirds.

-- 
tejun