On Mon, 23 Mar 2015 16:05:29 +0100 Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: > On Mo, 2015-03-23 at 15:54 +0100, Michael S. Tsirkin wrote: > > On Mon, Mar 23, 2015 at 03:27:35PM +0100, Gerd Hoffmann wrote: > > > Hi, > > > > > > > > > > You are doing leXXX everywhere, that's VERSION_1 dependency. > > > > > > > virtio_cread will do byteswaps differently without VERSION_1. > > > > > > > Just don't go there. > > > > > > > So to clarify, you dislike using __virtio32 in virtio input header? > > > > > > Well, as I understand things __virtio32 implies byteorder depends on > > > whenever we are using VERSION_1 or not. And non-transitional drivers > > > should not need it as everything is by definition little endian. > > > > > > So, yes, your suggestion to just require VERSION_1 in the driver implies > > > in my eyes that there should be no reason to use __virtio32 instead of > > > __le32. > > > > > > Or do I miss something here? > > > > > > cheers, > > > Gerd > > > > > > > You are right but then if you do require VERSION_1 then > > __virtio32 becomes identical to __le32. > > Except that sparse doesn't know that and throws errors when I mix the > two. > > > There's some runtime overhead as we check on each access, > > but it shouldn't matter here, right? > > Correct, config space is used at initialization time only. > > > I guess we could add virtio_cread_le - is this what > > you'd like? > > I just want something that makes both you and sparse happy. I don't > care much whenever that is adding virtio_cread_le() or using __virtio32 > even though it'll effectively is __le32 due to VERSION_1 being required. I think it is clearer if you use __virtio32: The fact that virtio-input is VERSION_1 only is not apparent from looking at the config space definition, and explicitly forcing le accesses makes it look similar to the oddballs like virtio-balloon. Just my two cents. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
