On Thu, Mar 30, 2023 at 10:49:26AM -0500, Bjorn Helgaas wrote: > On Thu, Mar 30, 2023 at 10:10:16AM +0800, Wu Zongyong wrote: > > On Wed, Mar 29, 2023 at 12:05:15PM -0500, Bjorn Helgaas wrote: > > > On Wed, Mar 29, 2023 at 07:58:45PM +0800, Wu Zongyong wrote: > > > > Secondary bus reset will fail if NVIDIA T4 card is direct attached to a > > > > root port. > > > > > > Is this only a problem when direct attached to a Root Port? Why would > > > that be? If it's *not* related to being directly under a Root Port, > > > don't mention that at all. > > > > Yes, this problem occurs only when the T4 card is direct attached to a > > Root Port. > > I have test it with a T4 card attached to a PCIe Switch or a PCI Bridge, > > and it works well. > > From an electrical and protocol point of view, the device should not > be able to tell the difference, so Lukas' suggestion that it may be > related to reset delays seems very pertinent. I will test it with the commits mentioned above. But it may take some time since it is not easy to replace kernel in our environment. > > Bjorn
