Mon, Jun 01, 2020 at 11:57:28AM CEST, vasundhara-v.vo...@broadcom.com wrote: >On Mon, Jun 1, 2020 at 3:19 PM Jiri Pirko <j...@resnulli.us> wrote: >> >> Mon, Jun 01, 2020 at 10:50:50AM CEST, vasundhara-v.vo...@broadcom.com wrote: >> >On Mon, Jun 1, 2020 at 12:09 PM Jiri Pirko <j...@resnulli.us> wrote: >> >> >> >> Wed, May 27, 2020 at 10:57:11PM CEST, michael.c...@broadcom.com wrote: >> >> >On Wed, May 27, 2020 at 1:14 PM Jakub Kicinski <k...@kernel.org> wrote: >> >> >> >> >> >> On Wed, 27 May 2020 09:07:09 +0530 Vasundhara Volam wrote: >> >> >> > Here is a sample sequence of commands to do a "live reset" to get >> >> >> > some >> >> >> > clear idea. >> >> >> > Note that I am providing the examples based on the current patchset. >> >> >> > >> >> >> > 1. FW live reset is disabled in the device/adapter. Here adapter has >> >> >> > 2 >> >> >> > physical ports. >> >> >> > >> >> >> > $ devlink dev >> >> >> > pci/0000:3b:00.0 >> >> >> > pci/0000:3b:00.1 >> >> >> > pci/0000:af:00.0 >> >> >> > $ devlink dev param show pci/0000:3b:00.0 name allow_fw_live_reset >> >> >> > pci/0000:3b:00.0: >> >> >> > name allow_fw_live_reset type generic >> >> >> > values: >> >> >> > cmode runtime value false >> >> >> > cmode permanent value false >> >> >> > $ 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 false >> >> >> > cmode permanent value false >> >> >> >> >> >> What's the permanent value? What if after reboot the driver is too old >> >> >> to change this, is the reset still allowed? >> >> > >> >> >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. >> >> > >> >> >> >> >> >> > 2. If a user issues "ethtool --reset p1p1 all", the device cannot >> >> >> > perform "live reset" as capability is not enabled. >> >> >> > >> >> >> > User needs to do a driver reload, for firmware to undergo reset. >> >> >> >> >> >> Why does driver reload have anything to do with resetting a potentially >> >> >> MH device? >> >> > >> >> >I think she meant that all drivers have to be unloaded before the >> >> >reset would take place in case it's a MH device since live reset is >> >> >not supported. If it's a single function device, unloading this >> >> >driver is sufficient. >> >> > >> >> >> >> >> >> > $ ethtool --reset p1p1 all >> >> >> >> >> >> Reset probably needs to be done via devlink. In any case you need a new >> >> >> reset level for resetting MH devices and smartnics, because the current >> >> >> reset mask covers port local, and host local cases, not any form of MH. >> >> > >> >> >RIght. This reset could be just a single function reset in this example. >> >> > >> >> >> >> >> >> > ETHTOOL_RESET 0xffffffff >> >> >> > Components reset: 0xff0000 >> >> >> > Components not reset: 0xff00ffff >> >> >> > $ dmesg >> >> >> > [ 198.745822] bnxt_en 0000:3b:00.0 p1p1: Firmware reset request >> >> >> > successful. >> >> >> > [ 198.745836] bnxt_en 0000:3b:00.0 p1p1: Reload driver to complete >> >> >> > reset >> >> >> >> >> >> You said the reset was not performed, yet there is no information to >> >> >> that effect in the log?! >> >> > >> >> >The firmware has been requested to reset, but the reset hasn't taken >> >> >place yet because live reset cannot be done. We can make the logs >> >> >more clear. >> >> > >> >> >> >> >> >> > 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). >> >> >> >> Ah, you need a reboot. I was not expecting that :/ So the "devlink dev >> >> reload" attr would not work for you. MLNX hardware can change this on >> >> runtime. >> > >> >NVRAM parameter configuration will take effect only on reboot or on >> >"live reset" (except few). But to enable "live reset", system needs a >> >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. >> >> >> >> This is a bit odd. It is a configuration, not an indication. When you >> >> want to indicate what you support something, I think it should be done >> >> in a different place. I think that "devlink dev info" is the place to >> >> put it, I think that we need "capabilities" there. >> >> >> >Indication can be shown in 'devlink dev info', but users can configure >> >this parameter also to control the 'live reset' at runtime. >> >> I'm totally confused. You wrote above that you need reboot (cmode >> permanent) for that. What is the usecase for cmode runtime? >> > >Okay let me brief it completely, probably some repetition. > >Permanent cmode, is to enable the "live reset" feature in the device, >which takes effect after reboot, as it is configuration the parameter >in NVRAM configuration. After reboot, if the parameter is enabled, >user can initiate the live reset from a separate command. > >Runtime cmode, default value is true and available only when permanent >cmode is true. This allows the user to temporarily disallow the "live >reset", if the host is running any mission critical application.
Okay. I understand now. Thanks.
