Oliver Neukum <oneukum@xxxxxxx> writes: > On Wed, 2013-09-18 at 20:56 +0200, Bjørn Mork wrote: >> Oliver Neukum <oneukum@xxxxxxx> wrote: > >> >No, USB 3.0 uses no companion controllers, so you can have devices >> >of any speed connected to it. >> > >> >> Ah, right. I don't own such modern hardware, but I should have known >> this anyway. >> >> This still doesn't change the fact that the driver is brand new for >> brand new devices. I believe we should assume such devices will >> support ZLPs unless we have documentation stating anything else. > > For such devices we might assume it. But how does that matter for > generic code? The code isn't generic yet. Most of it is placed inside the ax88179_178a minidriver. But I do agree that adding this padding support can be seen as one step towards making the code generic. So if you really anticipate this being enabled for e.g. the ECM class driver, then yes, padding must be supported. I would have had less trouble understanding the value if this patch was part of a generalisation series, though... > As any kind of device may be connected to XHCI, the sg > code is relevant for every driver. And I certainly don't want trouble > for older devices' drivers converted to sg. I wonder what the gain of that really is? Yes, I can see the advantage of making the class drivers more effective. But padding is only relevant for the ECM class, isn't it? And are there any ECM class devices where SG support matters? Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
