On Wed, Aug 5, 2020 at 12:02 PM Moshe Shemesh <mo...@mellanox.com> wrote: > > > On 8/4/2020 1:13 PM, Vasundhara Volam wrote: > > 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. > > > I see your point here, but the user run devlink reload command on one > PF, in this case of fw-reset it will influence other PFs, but that's a > result of the fw-reset, the user if asked for params change or namespace > change that was for this PF. Right, if any driver is implementing only fw-reset have to leave reload_up as an empty function.
> > >>> 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.
