Re: [patch] x86_64: fix boot time hang in detect_calgary()

[Muli Ben-Yehuda <muli@il.ibm.com>]

On Wed, Dec 20, 2006 at 11:53:32AM +0100, Ingo Molnar wrote:

> Index: linux/arch/x86_64/kernel/pci-calgary.c
> ===================================================================
> --- linux.orig/arch/x86_64/kernel/pci-calgary.c
> +++ linux/arch/x86_64/kernel/pci-calgary.c
> @@ -1052,7 +1052,7 @@ void __init detect_calgary(void)
>  	void *tbl;
>  	int calgary_found = 0;
>  	unsigned long ptr;
> -	int offset;
> +	unsigned int offset, prev_offset;
>  	int ret;
>  
>  	/*
> @@ -1071,15 +1071,20 @@ void __init detect_calgary(void)
>  	ptr = (unsigned long)phys_to_virt(get_bios_ebda());
>  
>  	rio_table_hdr = NULL;
> +	prev_offset = 0;
>  	offset = 0x180;
> -	while (offset) {
> +	/*
> +	 * The next offset is stored in the 1st word.
> +	 * Only parse up until the offset increases:
> +	 */
> +	while (offset > prev_offset) {
>  		/* The block id is stored in the 2nd word */
>  		if (*((unsigned short *)(ptr + offset + 2)) == 0x4752){
>  			/* set the pointer past the offset & block id */
>  			rio_table_hdr = (struct rio_table_hdr *)(ptr + offset + 4);
>  			break;
>  		}
> -		/* The next offset is stored in the 1st word. 0 means no more */
> +		prev_offset = offset;
>  		offset = *((unsigned short *)(ptr + offset));
>  	}
>  	if (!rio_table_hdr) {
> -

Patch looks good to me, thanks. I'll give it a spin to verify.

Please CC me on Calgary patches.

Cheers,
Muli