[PATCH] pata_platform struct resource signness fix

[PATCH] pata_platform struct resource signness fix

[Wang Jian]

Hi,

This patch is to pata_platform.c but at this time, it's powerpc specific
because it can only be triggerred using openfirmware, so I post the patch
here. The patch is against 2.6.26-rc8.

The problem is triggerred when ata device is populated using 
pata_of_platform.c, and no irq is assigned (poll mode, such as CF card).

pata_of_platform_probe() parse device tree and

        if (ret == NO_IRQ)
	                irq_res.start = irq_res.end = -1;

Then irq is 0xffffffff, not NULL. Probe will fail coz irq can't be
requested.


---
(irq_res->start > 0) will be true even when it is (-1). When the device
has no irq, irq_res->start is assigned (-1).

Signed-off-by: Wang Jian <lark@linux.net.cn>
---
 drivers/ata/pata_platform.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
index 8f65ad6..b12cd0c 100644
--- a/drivers/ata/pata_platform.c
+++ b/drivers/ata/pata_platform.c
@@ -123,7 +123,7 @@ int __devinit __pata_platform_probe(struct device *dev,
 	/*
 	 * And the IRQ
 	 */
-	if (irq_res && irq_res->start > 0) {
+	if (irq_res && irq_res->start != -1) {
 		irq = irq_res->start;
 		irq_flags = irq_res->flags;
 	}
-- 
1.5.5.4

Re: [PATCH] pata_platform struct resource signness fix

[Wang Jian]

The alternative fix can be.

diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
index 408da30..1f18ad9 100644
--- a/drivers/ata/pata_of_platform.c
+++ b/drivers/ata/pata_of_platform.c
@@ -52,7 +52,7 @@ static int __devinit pata_of_platform_probe(struct of_device *ofdev,

         ret = of_irq_to_resource(dn, 0, &irq_res);
         if (ret == NO_IRQ)
-               irq_res.start = irq_res.end = -1;
+               irq_res.start = irq_res.end = 0;
         else
                 irq_res.flags = 0;

I just didn't spend much time to see which is better.

Wang Jian wrote:
> Hi,
> 
> This patch is to pata_platform.c but at this time, it's powerpc specific
> because it can only be triggerred using openfirmware, so I post the patch
> here. The patch is against 2.6.26-rc8.
> 
> The problem is triggerred when ata device is populated using 
> pata_of_platform.c, and no irq is assigned (poll mode, such as CF card).
> 
> pata_of_platform_probe() parse device tree and
> 
>         if (ret == NO_IRQ)
> 	                irq_res.start = irq_res.end = -1;
> 
> Then irq is 0xffffffff, not NULL. Probe will fail coz irq can't be
> requested.
> 
> 
> ---
> (irq_res->start > 0) will be true even when it is (-1). When the device
> has no irq, irq_res->start is assigned (-1).
> 
> Signed-off-by: Wang Jian <lark@linux.net.cn>
> ---
>  drivers/ata/pata_platform.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
> index 8f65ad6..b12cd0c 100644
> --- a/drivers/ata/pata_platform.c
> +++ b/drivers/ata/pata_platform.c
> @@ -123,7 +123,7 @@ int __devinit __pata_platform_probe(struct device *dev,
>  	/*
>  	 * And the IRQ
>  	 */
> -	if (irq_res && irq_res->start > 0) {
> +	if (irq_res && irq_res->start != -1) {
>  		irq = irq_res->start;
>  		irq_flags = irq_res->flags;
>  	}

Re: [PATCH] pata_platform struct resource signness fix

[Leo Li]

On Thu, Sep 25, 2008 at 4:36 PM, Wang Jian <lark@linux.net.cn> wrote:
> Hi,
>
> This patch is to pata_platform.c but at this time, it's powerpc specific
> because it can only be triggerred using openfirmware, so I post the patch
> here. The patch is against 2.6.26-rc8.

Powerpc isn't the only arch to use openfirmware.  Anyway, you have to
cc linux-ide@vger.kernel.org if you want the patch to be merged.

- Leo

Re: [PATCH] pata_platform struct resource signness fix

[Wang Jian]

As I said, I didn't spend much time on the issue, so I don't know which patch
is better. (But I do think the patch to pata_of_platform.c is better ATM).

AFAIK, powerpc is the only consumer of pata_of_platform.c, so I think this list
is better for discussion.

I should cc: Anton Vorontsov <avorontsov@ru.mvista.com> but last time I cc:
him I got bounced.

Leo Li wrote:
> On Thu, Sep 25, 2008 at 4:36 PM, Wang Jian <lark@linux.net.cn> wrote:
>> Hi,
>>
>> This patch is to pata_platform.c but at this time, it's powerpc specific
>> because it can only be triggerred using openfirmware, so I post the patch
>> here. The patch is against 2.6.26-rc8.
> 
> Powerpc isn't the only arch to use openfirmware.  Anyway, you have to
> cc linux-ide@vger.kernel.org if you want the patch to be merged.
> 
> - Leo
> 
> 

Re: [PATCH] pata_platform struct resource signness fix

[Li Yang]

On Thu, Sep 25, 2008 at 4:54 PM, Wang Jian <lark@linux.net.cn> wrote:
> The alternative fix can be.

This one is better as 0 is defined as 'invalid irq' for all
architectures.  Added linux-ide and Anton to cc.

- Leo

>
> diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
> index 408da30..1f18ad9 100644
> --- a/drivers/ata/pata_of_platform.c
> +++ b/drivers/ata/pata_of_platform.c
> @@ -52,7 +52,7 @@ static int __devinit pata_of_platform_probe(struct
> of_device *ofdev,
>
>        ret = of_irq_to_resource(dn, 0, &irq_res);
>        if (ret == NO_IRQ)
> -               irq_res.start = irq_res.end = -1;
> +               irq_res.start = irq_res.end = 0;
>        else
>                irq_res.flags = 0;
>
> I just didn't spend much time to see which is better.
>
> Wang Jian wrote:
>>
>> Hi,
>>
>> This patch is to pata_platform.c but at this time, it's powerpc specific
>> because it can only be triggerred using openfirmware, so I post the patch
>> here. The patch is against 2.6.26-rc8.
>>
>> The problem is triggerred when ata device is populated using
>> pata_of_platform.c, and no irq is assigned (poll mode, such as CF card).
>>
>> pata_of_platform_probe() parse device tree and
>>
>>        if (ret == NO_IRQ)
>>                        irq_res.start = irq_res.end = -1;
>>
>> Then irq is 0xffffffff, not NULL. Probe will fail coz irq can't be
>> requested.
>>
>>
>> ---
>> (irq_res->start > 0) will be true even when it is (-1). When the device
>> has no irq, irq_res->start is assigned (-1).
>>
>> Signed-off-by: Wang Jian <lark@linux.net.cn>
>> ---
>>  drivers/ata/pata_platform.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
>> index 8f65ad6..b12cd0c 100644
>> --- a/drivers/ata/pata_platform.c
>> +++ b/drivers/ata/pata_platform.c
>> @@ -123,7 +123,7 @@ int __devinit __pata_platform_probe(struct device
>> *dev,
>>        /*
>>         * And the IRQ
>>         */
>> -       if (irq_res && irq_res->start > 0) {
>> +       if (irq_res && irq_res->start != -1) {
>>                irq = irq_res->start;
>>                irq_flags = irq_res->flags;
>>        }
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>

Re: [PATCH] pata_platform struct resource signness fix

[Anton Vorontsov]

On Thu, Sep 25, 2008 at 06:40:59PM +0800, Li Yang wrote:
> On Thu, Sep 25, 2008 at 4:54 PM, Wang Jian <lark@linux.net.cn> wrote:
> > The alternative fix can be.
> 
> This one is better as 0 is defined as 'invalid irq' for all
> architectures.  Added linux-ide and Anton to cc.

Thanks for the correct Cc.

I've sent a patch to fix the issue more than a month ago.

http://www.mail-archive.com/linuxppc-dev@ozlabs.org/msg22851.html

Jeff, could you apply the patch?

Thanks!

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2

Re: [PATCH] pata_platform struct resource signness fix

[Wang Jian]

Li Yang wrote:
> On Thu, Sep 25, 2008 at 4:54 PM, Wang Jian <lark@linux.net.cn> wrote:
>> The alternative fix can be.
> 
> This one is better as 0 is defined as 'invalid irq' for all
> architectures.  Added linux-ide and Anton to cc.

However, this is not very true. Just git grep "#define NO_IRQ" and see. It
seems that the NO_IRQ is in transition from (-1) to (0).

I happened to code the same 2 patches as Anton Vorontsov <avorontsov@ru.mvista.com>
had done without knowing his earlier work. I think he was also confused by (-1)
and (0).

> 
> - Leo
> 
>> diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
>> index 408da30..1f18ad9 100644
>> --- a/drivers/ata/pata_of_platform.c
>> +++ b/drivers/ata/pata_of_platform.c
>> @@ -52,7 +52,7 @@ static int __devinit pata_of_platform_probe(struct
>> of_device *ofdev,
>>
>>        ret = of_irq_to_resource(dn, 0, &irq_res);
>>        if (ret == NO_IRQ)
>> -               irq_res.start = irq_res.end = -1;
>> +               irq_res.start = irq_res.end = 0;
>>        else
>>                irq_res.flags = 0;
>>
>> I just didn't spend much time to see which is better.
>>
>> Wang Jian wrote:
>>> Hi,
>>>
>>> This patch is to pata_platform.c but at this time, it's powerpc specific
>>> because it can only be triggerred using openfirmware, so I post the patch
>>> here. The patch is against 2.6.26-rc8.
>>>
>>> The problem is triggerred when ata device is populated using
>>> pata_of_platform.c, and no irq is assigned (poll mode, such as CF card).
>>>
>>> pata_of_platform_probe() parse device tree and
>>>
>>>        if (ret == NO_IRQ)
>>>                        irq_res.start = irq_res.end = -1;
>>>
>>> Then irq is 0xffffffff, not NULL. Probe will fail coz irq can't be
>>> requested.
>>>
>>>
>>> ---
>>> (irq_res->start > 0) will be true even when it is (-1). When the device
>>> has no irq, irq_res->start is assigned (-1).
>>>
>>> Signed-off-by: Wang Jian <lark@linux.net.cn>
>>> ---
>>>  drivers/ata/pata_platform.c |    2 +-
>>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
>>> index 8f65ad6..b12cd0c 100644
>>> --- a/drivers/ata/pata_platform.c
>>> +++ b/drivers/ata/pata_platform.c
>>> @@ -123,7 +123,7 @@ int __devinit __pata_platform_probe(struct device
>>> *dev,
>>>        /*
>>>         * And the IRQ
>>>         */
>>> -       if (irq_res && irq_res->start > 0) {
>>> +       if (irq_res && irq_res->start != -1) {
>>>                irq = irq_res->start;
>>>                irq_flags = irq_res->flags;
>>>        }
>> _______________________________________________
>> Linuxppc-dev mailing list
>> Linuxppc-dev@ozlabs.org
>> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>>
> 
> 

Re: [PATCH] pata_platform struct resource signness fix

[Anton Vorontsov]

On Thu, Sep 25, 2008 at 11:33:35PM +0800, Wang Jian wrote:
> Li Yang wrote:
>> On Thu, Sep 25, 2008 at 4:54 PM, Wang Jian <lark@linux.net.cn> wrote:
>>> The alternative fix can be.
>>
>> This one is better as 0 is defined as 'invalid irq' for all
>> architectures.  Added linux-ide and Anton to cc.
>
> However, this is not very true. Just git grep "#define NO_IRQ" and see. It
> seems that the NO_IRQ is in transition from (-1) to (0).

Yeah, there is a mess, but it gets better as time goes by.
The platforms/drivers should be fixed, since 0 is the only
invalid VIRQ.

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2

Re: [PATCH] pata_platform struct resource signness fix

[Jeff Garzik]

Anton Vorontsov wrote:
> On Thu, Sep 25, 2008 at 06:40:59PM +0800, Li Yang wrote:
>> On Thu, Sep 25, 2008 at 4:54 PM, Wang Jian <lark@linux.net.cn> wrote:
>>> The alternative fix can be.
>> This one is better as 0 is defined as 'invalid irq' for all
>> architectures.  Added linux-ide and Anton to cc.
> 
> Thanks for the correct Cc.
> 
> I've sent a patch to fix the issue more than a month ago.
> 
> http://www.mail-archive.com/linuxppc-dev@ozlabs.org/msg22851.html
> 
> Jeff, could you apply the patch?

Can you resend, I don't seem to have it...

[PATCH] pata_of_platform: fix no irq handling

[Anton Vorontsov]

When no irq specified the pata_of_platform fills the irq_res with -1,
which is wrong to do for two reasons:

1. By definition, 'no irq' should be IRQ 0, not some negative integer;
2. pata_platform checks for irq_res.start > 0, but since irq_res.start
   is unsigned type, the check will be true for `-1'.

Reported-by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---

On Mon, Sep 29, 2008 at 12:19:14AM -0400, Jeff Garzik wrote:
> Anton Vorontsov wrote:
>> On Thu, Sep 25, 2008 at 06:40:59PM +0800, Li Yang wrote:
>>> On Thu, Sep 25, 2008 at 4:54 PM, Wang Jian <lark@linux.net.cn> wrote:
>>>> The alternative fix can be.
>>> This one is better as 0 is defined as 'invalid irq' for all
>>> architectures.  Added linux-ide and Anton to cc.
>>
>> Thanks for the correct Cc.
>>
>> I've sent a patch to fix the issue more than a month ago.
>>
>> http://www.mail-archive.com/linuxppc-dev@ozlabs.org/msg22851.html
>>
>> Jeff, could you apply the patch?
>
> Can you resend, I don't seem to have it...

Here it is.

Thanks,

 drivers/ata/pata_of_platform.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
index 408da30..1f18ad9 100644
--- a/drivers/ata/pata_of_platform.c
+++ b/drivers/ata/pata_of_platform.c
@@ -52,7 +52,7 @@ static int __devinit pata_of_platform_probe(struct of_device *ofdev,
 
 	ret = of_irq_to_resource(dn, 0, &irq_res);
 	if (ret == NO_IRQ)
-		irq_res.start = irq_res.end = -1;
+		irq_res.start = irq_res.end = 0;
 	else
 		irq_res.flags = 0;
 
-- 
1.5.6.3