Re: [PATCH] PCIe: Designware: Do not allow config space through ranges

[Pratyush Anand <panand@redhat.com>]

On Monday 22 December 2014 02:00 PM, Arnd Bergmann wrote:
> On Monday 22 December 2014 12:09:04 Pratyush Anand wrote:
>> Config space is need to be allocated using reg property. This patch
>> removes possibility of config space allocation through ranges property.
>>
>> To: Mohit Kumar <mohit.kumar@st.com>
>> To: Jingo Han <jg1.han@samsung.com>
>> To: Lucas Stach <l.stach@pengutronix.de>
>> To: Shawn Guo <shawn.guo@freescale.com>
>> Cc: linux-pci@vger.kernel.org
>> Cc: devicetree@vger.kernel.org
>> Signed-off-by: Pratyush Anand <panand@redhat.com>
>> ---
>>   arch/arm/boot/dts/imx6qdl.dtsi     |  3 +--
>>   arch/arm/boot/dts/imx6sx.dtsi      |  8 ++++----
>
> changing the DT files is probably ok.
>
>> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
>> index df781cdf13c1..0b22b42e1ff9 100644
>> --- a/drivers/pci/host/pcie-designware.c
>> +++ b/drivers/pci/host/pcie-designware.c
>> @@ -409,19 +409,6 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
>>   			pp->mem_mod_base = of_read_number(parser.range -
>>   							  parser.np + na, ns);
>>   		}
>> -		if (restype == 0) {
>> -			of_pci_range_to_resource(&range, np, &pp->cfg);
>> -			pp->cfg0_size = resource_size(&pp->cfg)/2;
>> -			pp->cfg1_size = resource_size(&pp->cfg)/2;
>> -			pp->cfg0_base = pp->cfg.start;
>> -			pp->cfg1_base = pp->cfg.start + pp->cfg0_size;
>> -
>> -			/* Find the untranslated configuration space address */
>> -			pp->cfg0_mod_base = of_read_number(parser.range -
>> -							   parser.np + na, ns);
>> -			pp->cfg1_mod_base = pp->cfg0_mod_base +
>> -					    pp->cfg0_size;
>> -		}
>>   	}
>
> Since we've allowed this for so long, it may be better to leave this
> in for compatibility with old dts files. It would however be good to
> print a warning message. We could also limit it to those machines that
> are known to have been used with this property in the past.

I think, only imx6 is using "config from ranges", for which I made the 
change in this patch. Modification need to be tested and acked by IMX6 
maintainers.
I do not see any other driver using it. However, I have kept all 
designware user in CC here.

~Pratyush


>
> 	Arnd
>