Messages in this thread | | | Subject | Re: [PATCH v5 0/7] can: refactoring of can-dev module and of Kbuild | From | Oliver Hartkopp <> | Date | Tue, 7 Jun 2022 22:12:46 +0200 |
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Hi Vincent,
On 07.06.22 04:49, Vincent MAILHOL wrote: > On Tue. 7 Jun. 2022 at 04:43, Oliver Hartkopp <socketcan@hartkopp.net> wrote: >>
>>> | >>> +-> All other CAN devices not relying on RX offload >>> | >>> +-> CAN rx offload >>> symbol: CONFIG_CAN_RX_OFFLOAD >> >> Is this still true in patch series 5? >> >> If I understood it correctly CONFIG_CAN_BITTIMING and >> CONFIG_CAN_RX_OFFLOAD can be enabled by the user and >> (alternatively/additionally) the selection of "flexcan, m_can, mcp251xfd >> and ti_hecc" enables CONFIG_CAN_RX_OFFLOAD too. >> >> Right? > > Yes, this is correct. Maybe what troubles you is the meaning of the > "x --> y" arrow in the graph. I said it denotes that "y depends on x". > Here "depends on" has a loose meaning. It translates to either: > * Feature Y is encapsulated in Kbuild by some "if X/endif" and won't > show up unless X is selected. > * Feature Y has a "selects X" tag and will forcibly enable X if selected. > > CONFIG_CAN_*CALC*_BITTIMING is on the left side of an arrow starting > from CONFIG_CAN_NETLINK so it "depends" on CONFIG_CAN_NETLINK. On the > other hand, CONFIG_CAN_*CALC*_BITTIMING does not have any arrow > starting from it so indeed, it can be enabled by the user > independently of the other features as long as CONFIG_CAN_NETLINK is > selected.
Ok.
> CONFIG_CAN_RX_OFFLOAD is also on the left side of an arrow starting > from CONFIG_CAN_NETLINK. Furthermore, there is an arrow starting from > CONFIG_CAN_RX_OFFLOAD going to the "rx offload drivers". So those > drivers need CONFIG_CAN_RX_OFFLOAD (which is implemented using the > "selects CONFIG_CAN_RX_OFFLOAD"). However, CONFIG_CAN_RX_OFFLOAD can > be selected independently of the "rx offload drivers" as long as its > CONFIG_CAN_NETLINK dependency is met. > > So I think that the diagram is correct. Maybe rephrasing the cover > letter as below would address your concerns? I applied your series and played with the options and it works like charm - and as expected.
But the point remains that from your figure I would still assume that the M_CAN driver would only show up when CONFIG_CAN_RX_OFFLOAD was selected by the user.
But the current (good) implementation shows *all* drivers and selects CONFIG_CAN_RX_OFFLOAD when e.g. M_CAN is selected.
So what about:
symbol: CONFIG_NETDEVICES | +-> CAN Device Drivers symbol: CONFIG_CAN_DEV | +-> software/virtual CAN device drivers | (at time of writing: slcan, vcan, vxcan) | +-> hardware CAN device drivers with Netlink support symbol: CONFIG_CAN_NETLINK (matches previous CONFIG_CAN_DEV) | +-> CAN bit-timing calculation (optional for all drivers) | symbol: CONFIG_CAN_BITTIMING | +-> CAN rx offload (optional but selected by some drivers) | symbol: CONFIG_CAN_RX_OFFLOAD | +-> CAN devices drivers (some may select CONFIG_CAN_RX_OFFLOAD)
(I also added 'hardware' to CAN device drivers with Netlink support) to have a distinction to 'software/virtual' CAN device drivers)
At least this would help me to understand the new configuration setup.
Best regards, Oliver
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