On Mon, Aug 3, 2020 at 7:23 PM Moshe Shemesh <mo...@mellanox.com> wrote: > > > On 8/3/2020 3:47 PM, Vasundhara Volam wrote: > > On Mon, Aug 3, 2020 at 5:47 PM Moshe Shemesh <mo...@mellanox.com> wrote: > >> > >> On 8/3/2020 1:24 PM, Vasundhara Volam wrote: > >>> On Tue, Jul 28, 2020 at 10:13 PM Jacob Keller <jacob.e.kel...@intel.com> > >>> wrote: > >>>> > >>>> On 7/27/2020 10:25 PM, Vasundhara Volam wrote: > >>>>> On Mon, Jul 27, 2020 at 4:36 PM Moshe Shemesh <mo...@mellanox.com> > >>>>> wrote: > >>>>>> Introduce new option on devlink reload API to enable the user to > >>>>>> select the > >>>>>> reload level required. Complete support for all levels in mlx5. > >>>>>> The following reload levels are supported: > >>>>>> driver: Driver entities re-instantiation only. > >>>>>> fw_reset: Firmware reset and driver entities re-instantiation. > >>>>> The Name is a little confusing. I think it should be renamed to > >>>>> fw_live_reset (in which both firmware and driver entities are > >>>>> re-instantiated). For only fw_reset, the driver should not undergo > >>>>> reset (it requires a driver reload for firmware to undergo reset). > >>>>> > >>>> So, I think the differentiation here is that "live_patch" doesn't reset > >>>> anything. > >>> This seems similar to flashing the firmware and does not reset anything. > >> > >> The live patch is activating fw change without reset. > >> > >> It is not suitable for any fw change but fw gaps which don't require reset. > >> > >> I can query the fw to check if the pending image change is suitable or > >> require fw reset. > > Okay. > >>>>>> fw_live_patch: Firmware live patching only. > >>>>> This level is not clear. Is this similar to flashing?? > >>>>> > >>>>> Also I have a basic query. The reload command is split into > >>>>> reload_up/reload_down handlers (Please correct me if this behaviour is > >>>>> changed with this patchset). What if the vendor specific driver does > >>>>> not support up/down and needs only a single handler to fire a firmware > >>>>> reset or firmware live reset command? > >>>> In the "reload_down" handler, they would trigger the appropriate reset, > >>>> and quiesce anything that needs to be done. Then on reload up, it would > >>>> restore and bring up anything quiesced in the first stage. > >>> Yes, I got the "reload_down" and "reload_up". Similar to the device > >>> "remove" and "re-probe" respectively. > >>> > >>> But our requirement is a similar "ethtool reset" command, where > >>> ethtool calls a single callback in driver and driver just sends a > >>> firmware command for doing the reset. Once firmware receives the > >>> command, it will initiate the reset of driver and firmware entities > >>> asynchronously. > >> > >> It is similar to mlx5 case here for fw_reset. The driver triggers the fw > >> command to reset and all PFs drivers gets events to handle and do > >> re-initialization. To fit it to the devlink reload_down and reload_up, > >> I wait for the event handler to complete and it stops at driver unload > >> to have the driver up by devlink reload_up. See patch 8 in this patchset. > >> > > Yes, I see reload_down is triggering the reset. In our driver, after > > triggering the reset through a firmware command, reset is done in > > another context as the driver initiates the reset only after receiving > > an ASYNC event from the firmware. > > > Same here. > > > > > Probably, we have to use reload_down() to send firmware command to > > trigger reset and do nothing in reload_up. > I had that in previous version, but its wrong to use devlink reload this > way, so I added wait with timeout for the event handling to complete > before unload_down function ends. See mlx5_fw_wait_fw_reset_done(). Also > the event handler stops before load back to have that done by devlink > reload_up. But "devlink dev reload" will be invoked by the user only on a single dev handler and all function drivers will be re-instantiated upon the ASYNC event. reload_down and reload_up are invoked only the function which the user invoked.
Take an example of a 2-port (PF0 and PF1) adapter on a single host and with some VFs loaded on the device. User invokes "devlink dev reload" on PF0, ASYNC event is received on 2 PFs and VFs for reset. All the function drivers will be re-instantiated including PF0. If we wait for some time in reload_down() of PF0 and then call load in reload_up(), this code will be different from other function drivers. > > And returning from reload > > does not mean that reset is complete as it is done in another context > > and the driver notifies the health reporter once the reset is > > complete. devlink framework may have to allow drivers to implement > > reload_down only to look more clean or call reload_up only if the > > driver notifies the devlink once reset is completed from another > > context. Please suggest.
