Re: [PATCH v11 08/10] OF: PCI: Add support for parsing PCI host bridge resources from DT

[Liviu Dudau]

On Mon, Sep 22, 2014 at 10:32:28AM +0100, Robert Richter wrote:
> On 18.09.14 02:30:23, Liviu Dudau wrote:
> > +int of_pci_get_host_bridge_resources(struct device_node *dev,
> > +			unsigned char busno, unsigned char bus_max,
> > +			struct list_head *resources, resource_size_t *io_base)
> > +{
> > +	struct resource *res;
> > +	struct resource *bus_range;
> > +	struct of_pci_range range;
> > +	struct of_pci_range_parser parser;
> > +	char range_type[4];
> > +	int err;
> > +
> > +	if (!io_base)
> > +		return -EINVAL;
> > +	*io_base = OF_BAD_ADDR;
> 

Hi Robert,

> This breaks for mem-mapped pci host controllers. The patch below fixes
> this.

I think you mean PCI host controller that have only memory mapped ranges,
am I right? Initially I've read your reply as to mean that the host
controller is accessed through some memory mapped area, which I believe is
the case for all host controllers.

> 
> This series was tested with the fix on top for Cavium Thunder.
> 
> Tested-by: Robert Richter <rrichter@xxxxxxxxxx>

Thanks for that!

> 
> -Robert
> 
> 
> 
> From e798af4fc2f664d1aff7e863489b8298f90e716e Mon Sep 17 00:00:00 2001
> From: Robert Richter <rrichter@xxxxxxxxxx>
> Date: Mon, 22 Sep 2014 10:46:01 +0200
> Subject: [PATCH] OF: PCI: Fix creation of mem-mapped pci host bridges
> 
> The pci host bridge was not created if io_base was not set when
> calling of_pci_get_host_bridge_resources(). This is esp. the case for
> mem-mapped io (IORESOURCE_MEM). This patch fixes this. Function
> parameter io_base is optional now.

I think the message is misleading. What you want to do is make io_base
optional for the case where the PCI host bridge only expects to have only
IORESOURCE_MEM ranges and doesn't care about IORESOURCE_IO ones.

As I'm going to touch this area again to address a comment from Bjorn,
do you mind if I roll this patch into mine with your Signed-off-by and
the mention that you have made io_base optional?

Best regards,
Liviu

> 
> Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
> ---
>  drivers/of/of_pci.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index ffdb45ed8682..1f0e7c2505ee 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -182,9 +182,8 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
>  	char range_type[4];
>  	int err;
>  
> -	if (!io_base)
> -		return -EINVAL;
> -	*io_base = OF_BAD_ADDR;
> +	if (io_base)
> +		*io_base = OF_BAD_ADDR;
>  
>  	bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
>  	if (!bus_range)
> @@ -242,7 +241,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
>  			goto parse_failed;
>  		}
>  
> -		if (resource_type(res) == IORESOURCE_IO) {
> +		if (io_base && resource_type(res) == IORESOURCE_IO) {
>  			if (*io_base != OF_BAD_ADDR)
>  				pr_warn("More than one I/O resource converted. CPU offset for old range lost!\n");
>  			*io_base = range.cpu_addr;
> -- 
> 2.1.0
> 
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