[U-Boot] [PATCH v3 06/10] MIPS: qemu-malta: add PCI support

[Daniel Schwierzeck]

Hi Tom, Wolfgang,

we do not have a dedicated PCI custodian so could you comment this
please? Thanks.

2013/5/23 Gabor Juhos <juhosg at openwrt.org>:
> Hi Daniel,
>
> Thank you for the review!
>
>> 2013/5/22 Gabor Juhos <juhosg at openwrt.org>:
>>> Qemu emulates the Galileo GT64120 System Controller
>>> which provides a CPU bus to PCI bus bridge.
>>>
>>> The patch adds driver for this bridge and enables
>>> PCI support for the emulated Malta board.
>>>
>>> Signed-off-by: Gabor Juhos <juhosg at openwrt.org>
>>> Cc: Daniel Schwierzeck <daniel.schwierzeck at googlemail.com>
>>
>>
>> ELDK-5.3 shows some warnings:
>>
>> pci_indirect.c: In function 'indirect_read_config_byte':
>> pci_indirect.c:101:1: warning: implicit declaration of function
>> 'out_le32' [-Wimplicit-function-declaration]
>> pci_indirect.c:101:1: warning: implicit declaration of function 'in_8'
>> [-Wimplicit-function-declaration]
>> pci_indirect.c: In function 'indirect_read_config_word':
>> pci_indirect.c:102:1: warning: implicit declaration of function
>> 'in_le16' [-Wimplicit-function-declaration]
>> pci_indirect.c: In function 'indirect_read_config_dword':
>> pci_indirect.c:103:1: warning: implicit declaration of function
>> 'in_le32' [-Wimplicit-function-declaration]
>> pci_indirect.c: In function 'indirect_write_config_byte':
>> pci_indirect.c:109:1: warning: implicit declaration of function
>> 'out_8' [-Wimplicit-function-declaration]
>> pci_indirect.c: In function 'indirect_write_config_word':
>> pci_indirect.c:110:1: warning: implicit declaration of function
>> 'out_le16' [-Wimplicit-function-declaration]
>
> Hm, you are right. My toolchain also shows the warning but I did not notice
> those because I forgot to redirect stderr when I have generated the build logs.
>
> The pci_indirect.c file is always compiled when CONFIG_PCI is defined although
> it is not needed at all for Malta PCI support.
>
> The issue can be resolved on a few different ways:
>
> 1. Extend the '#if !defined(__I386__)' directive in pci_indirect.c with a new
> '&& !defined(__MIPS__)' condition. This would be the simplest solution but the
> drawback of this is that indirect support will not be usable on any MIPS board.
>
> 2. Introduce a new 'CONFIG_PCI_INDIRECT_BRIDGE' option and only compile the
> pci_indirect.c file if this option is present. Probably this is the best
> solution however the new symbol should be added into the configuration of the
> affected boards.
>
> 3. Introduce a new 'CONFIG_PCI_NO_INDIRECT_BRIDGE' option and use an '#ifndef
> CONFIG_PCI_NO_INDIRECT_BRIDGE' directive in pci_indirect.c.
>
> I'm unsure about which approach is preferred.
>

I favor the second option.

--
Best regards,
Daniel