On Fri, May 29, 2020 at 12:35 AM Jakub Kicinski <k...@kernel.org> wrote: > > On Thu, 28 May 2020 07:20:00 +0530 Vasundhara Volam wrote: > > > > The permanent value should be the NVRAM value. If the NVRAM value is > > > > false, the feature is always and unconditionally disabled. If the > > > > permanent value is true, the feature will only be available when all > > > > loaded drivers indicate support for it and set the runtime value to > > > > true. If an old driver is loaded afterwards, it wouldn't indicate > > > > support for this feature and it wouldn't set the runtime value to > > > > true. So the feature will not be available until the old driver is > > > > unloaded or upgraded. > > > > > > Setting this permanent value to false makes the FW's life easier? > > > > It just disables the feature. > > > > > Otherwise why not always have it enabled and just depend on hosts > > > not opting in? > > > > We are providing permanent value as a flexibility to user. We can > > remove it, if it makes things easy and clear. > > I'd think less knobs means less to understand for the user and less > to test for the vendor. If disabling the feature doesn't buy FW > anything then perhaps it can just serve the purpose of setting the > default? > > > > > > > 3. Now enable the capability in the device and reboot for device to > > > > > > enable the capability. Firmware does not get reset just by setting > > > > > > the > > > > > > param to true. > > > > > > > > > > > > $ devlink dev param set pci/0000:3b:00.1 name allow_fw_live_reset > > > > > > value true cmode permanent > > > > > > > > > > > > 4. After reboot, values of param. > > > > > > > > > > Is the reboot required here? > > > > > > > > In general, our new NVRAM permanent parameters will take effect after > > > > reset (or reboot). > > > > > > > > > > $ devlink dev param show pci/0000:3b:00.1 name allow_fw_live_reset > > > > > > pci/0000:3b:00.1: > > > > > > name allow_fw_live_reset type generic > > > > > > values: > > > > > > cmode runtime value true > > > > > > > > > > Why is runtime value true now? > > > > > > > > > > > > > If the permanent (NVRAM) parameter is true, all loaded new drivers > > > > will indicate support for this feature and set the runtime value to > > > > true by default. The runtime value would not be true if any loaded > > > > driver is too old or has set the runtime value to false. > > > > > > Okay, the parameter has a bit of a dual role as it controls whether the > > > feature is available (false -> true transition requiring a reset/reboot) > > > and the default setting of the runtime parameter. Let's document that > > > more clearly. > > Please look at the 3/4 patch for more documentation in the bnxt.rst > > file. We can add more documentation, if needed, in the bnxt.rst file. > > Ack, I read that, but it wasn't nearly clear enough. The command > examples helped much more. I think the doc should be expanded. Thank you for looking into it. I will soon send out the next version of patchset with expanded documentation and param is split into two with better renaming.
Thanks.
