[SeaBIOS] [PATCH v3 2/5] hw/pci: introduce pcie-pci-bridge device

[Marcel Apfelbaum]

On 01/08/2017 18:51, Michael S. Tsirkin wrote:
> On Tue, Aug 01, 2017 at 06:45:13PM +0300, Marcel Apfelbaum wrote:
>> On 01/08/2017 18:32, Michael S. Tsirkin wrote:
>>> On Mon, Jul 31, 2017 at 09:40:41PM +0300, Alexander Bezzubikov wrote:
>>>>>> +typedef struct PCIEPCIBridge {
>>>>>> +    /*< private >*/
>>>>>> +    PCIBridge parent_obj;
>>>>>> +
>>>>>> +    bool msi_enable;
>>>>>
>>>>>
>>>>> Please rename the msi_enable property to "msi" in order
>>>>> to be aligned with the existent PCIBridgeDev and
>>>>> consider making it OnOffAuto for the same reason.
>>>>> (I am not sure about the last part though, we have
>>>>>    no meaning for "auto" here)
>>>>>
>>>>
>>>> Agreed about "msi", but OnOffAuto looks weird to me
>>>> as we always want MSI to be enabled.
>>>
>>
>> Hi Michael,
>>
>>> Why even have a property then? Can't you enable it unconditionally?
>>>
>>
>> Because of a current bug in Linux kernel:
>>     https://www.spinics.net/lists/linux-pci/msg63052.html
>> msi will not work until the patch is merged. Even when
>> it will be merged, not all linux kernels will contain the patch.
> 
> You should Cc stable to make sure they all gain it eventually.
> 

Right! thanks, we missed cc-ing stable.
Added stable to the mail thread.
Marcel


>> Disabling msi is a workaround for the above case.
>>
>> Thanks,
>> Marcel
> 
> Really enabling MSI without bus master is a bug that I'm not 100% sure
> it even worth working around. But I guess it's not too bad to have a
> work-around given it's this simple.
>