Re: [Qemu-devel] Re: [PATCH V5 07/29] pci/bridge: clean up of pci_bridge_initfn()

[Blue Swirl]

On Tue, Oct 13, 2009 at 4:20 PM, Isaku Yamahata <address@hidden> wrote:
> On Fri, Oct 09, 2009 at 08:53:10AM +0200, Michael S. Tsirkin wrote:
>> On Fri, Oct 09, 2009 at 03:28:40PM +0900, Isaku Yamahata wrote:
>> > - use symbolic constant
>> > - use helper function pci_set_xxx()
>> >
>> > Signed-off-by: Isaku Yamahata <address@hidden>
>> > ---
>> >  hw/pci.c |   23 ++++++++++++-----------
>> >  1 files changed, 12 insertions(+), 11 deletions(-)
>> >
>> > diff --git a/hw/pci.c b/hw/pci.c
>> > index a66e3de..eaf471a 100644
>> > --- a/hw/pci.c
>> > +++ b/hw/pci.c
>> > @@ -923,17 +923,18 @@ static int pci_bridge_initfn(PCIDevice *dev)
>> >      pci_config_set_vendor_id(s->dev.config, s->vid);
>> >      pci_config_set_device_id(s->dev.config, s->did);
>> >
>> > -    s->dev.config[0x04] = 0x06; // command = bus master, pci mem
>> > -    s->dev.config[0x05] = 0x00;
>> > -    s->dev.config[0x06] = 0xa0; // status = fast back-to-back, 66MHz, no 
>> > error
>> > -    s->dev.config[0x07] = 0x00; // status = fast devsel
>> > -    s->dev.config[0x08] = 0x00; // revision
>> > -    s->dev.config[0x09] = 0x00; // programming i/f
>> > -    pci_config_set_class(s->dev.config, PCI_CLASS_BRIDGE_PCI);
>> > -    s->dev.config[0x0D] = 0x10; // latency_timer
>> > -    s->dev.config[PCI_HEADER_TYPE] =
>> > -        PCI_HEADER_TYPE_MULTI_FUNCTION | PCI_HEADER_TYPE_BRIDGE; // 
>> > header_type
>> > -    s->dev.config[0x1E] = 0xa0; // secondary status
>> > +    pci_set_word(dev->config + PCI_COMMAND,
>> > +                 PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
>>
>> BTW, I think this is a wrong reset value: should be disabled
>> by default. Fixing this needs some testing though, so
>> I am not suggesting we do it in this patch. Have some time
>> to fix this?
>
> Hmm, the user of it is only apb_pci.c
> I guess other magic values came from the real machine.
> So one possible fix is to create apb_pci specific initialization function
> and to move those initialization code into apb_pci.c leaving to
> sparc guys. So we can avoid breakage.
> What do you think of it?

Current code is buggy. According to manual (805-1251) the reset value
should be zero, unless the boot pin is tied high (which is true) and
thus it should be PCI_COMMAND_MEMORY.

I think the default value should be zero and this should be overridden
later in apb_pci.c.