On Fri, Sep 22, 2023 at 12:25:06PM +0000, Parav Pandit wrote: > > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Sent: Friday, September 22, 2023 5:53 PM > > > > > And what's more, using MMIO BAR0 then it can work for legacy. > > > > Oh? How? Our team didn't think so. > > It does not. It was already discussed. > The device reset in legacy is not synchronous. > The drivers do not wait for reset to complete; it was written for the sw backend. > Hence MMIO BAR0 is not the best option in real implementations. Or maybe they made it synchronous in hardware, that's all. After all same is true for the IO BAR0 e.g. for the PF: IO writes are posted anyway. Whether that's possible would depend on the hardware architecture. -- MST
