Re: [PATCH] pci-e: ignore unknown capability and continue searching

["Zhang, Yanmin" <yanmin_zhang@linux.intel.com>]

Greg, Jesse,

Is there any issue with the patch? Tomasz need kernel to have the patch to work
on his machine.

Thanks,
Yanmin

On Tue, 2008-09-30 at 12:29 +0800, Zhang, Yanmin wrote:
> Subject: pci-e: ignore unknown capability and continue searching
> From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
> 
> 
> Tomasz reported AER driver couldn't work on his machine. With the output
> of "lcpsi -vvv", I found the root port's extended capabilities are
>          Capabilities: [100] Unknown (11)
>          Capabilities: [150] Advanced Error Reporting
>          Capabilities: [190] Unknown (13)
> Such Unknown capability is not expected. During pci-e initialization,function
> get_port_device_capability just returns if it hits an unknown capability when
> searching the AER capability.
> 
> I worked out a patch against 2.6.27-rc7. When hitting an unkown capability,
> function get_port_device_capability continues the searching.
> 
> Tomasz tested it and the patch does work well.
> 
> Signed-off-by Zhang Yanmin <yanmin.zhang@linux.intel.com>
> Reported-by Tomasz Czernecki <czernecki@gmail.com>
> 
> ---
> 
> --- linux-2.6.27-rc7/drivers/pci/pcie/portdrv_core.c	2008-09-27 09:35:32.000000000 +0800
> +++ linux-2.6.27-rc7_aer/drivers/pci/pcie/portdrv_core.c	2008-09-27 10:10:39.000000000 +0800
> @@ -195,23 +195,25 @@ static int get_port_device_capability(st
>  	/* PME Capable - root port capability */
>  	if (((reg16 >> 4) & PORT_TYPE_MASK) == PCIE_RC_PORT)
>  		services |= PCIE_PORT_SERVICE_PME;
> -	
> +
>  	pos = PCI_CFG_SPACE_SIZE;
>  	while (pos) {
> -		pci_read_config_dword(dev, pos, &reg32);
> -		switch (reg32 & 0xffff) {
> +		if (pci_read_config_dword(dev, pos, &reg32))
> +			break;
> +
> +		/* some broken boards return ~0 */
> +		if (reg32 == 0xffffffff)
> +			break;
> +
> +		switch (PCI_EXT_CAP_ID(reg32)) {
>  		case PCI_EXT_CAP_ID_ERR:
>  			services |= PCIE_PORT_SERVICE_AER;
> -			pos = reg32 >> 20;
>  			break;
>  		case PCI_EXT_CAP_ID_VC:
>  			services |= PCIE_PORT_SERVICE_VC;
> -			pos = reg32 >> 20;
> -			break;
> -		default:
> -			pos = 0;
>  			break;
>  		}
> +		pos = PCI_EXT_CAP_NEXT(reg32);
>  	}
>  
>  	return services;
> 
> 
> 
> --
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