[OpenBIOS] [PATCH v3] Add USB OHCI + HID driver

[BALATON Zoltan]

On Thu, 26 Jun 2014, Alexander Graf wrote:
> On 01.06.14 23:55, BALATON Zoltan wrote:
>> This driver is ported from CoreBoot's libpayload and fixed to work on
>> big endian CPUs (tested on PPC with QEMU). It is enough to support a
>> USB keyboard on an Apple Keylargo OHCI compliant USB host and makes
>> OpenBIOS usable on qemu-system-ppc64 with mac99 machine type as well
>> as allows to emulate PowerMac3,1 better.
>> 
>> Signed-off-by: BALATON Zoltan <balaton at eik.bme.hu>
>> Acked-by: Alexander Graf <agraf at suse.de>
>> ---
>> 
>> v2: improve init and teardown by moving pci configuration to the driver
>>      and giving up using the controller on quiesce interface call also
>>      resetting it to avoid runaway DMA until the OS driver takes over
>> v3: Only enable bus master bit in PCI config for QEMU
>> ---
>
> [...]
>
>> +hci_t *
>> +ohci_pci_init (pci_addr addr)
>> +{
>> +	u32 reg_base;
>> +#if defined(CONFIG_QEMU)
>> +	uint16_t cmd;
>> +
>> +	cmd = pci_config_read16(addr, PCI_COMMAND);
>> +	cmd |= PCI_COMMAND_BUS_MASTER;
>> +	pci_config_write16(addr, PCI_COMMAND, cmd);
>> +#endif
>
> I don't think the driver will work without bus mastering.

So then apply the first version without this #if.

> Just don't match on 
> it on non-QEMU machines and add a comment why you don't.

Why not? Coreboot is supposed to work on real hardware too. Does OpenBIOS 
work on any? If not why make it more complicated than it needs to be? 
There has to be an end somewhere for putting conditionals everywhere. The 
next person that tests OpenBIOS on something where this driver does not 
work can special case that but until then why can't we assume it should 
work?

Regards,
BALATON Zoltan