Subject: Re: [PATCH] pata_platform struct resource signness fix

From: Wang Jian <[email-masked]>
Date: Thu, 25 Sep 2008 16:54:27 +0800

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 <[email-masked]>
> ---
>  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;
>  	}