From: Clay McClure clay@daemons.net
[ Upstream commit b6d49cab44b567b3e0a5544b3d61e516a7355fad ]
Commit d1cbfd771ce8 ("ptp_clock: Allow for it to be optional") changed all PTP-capable Ethernet drivers from `select PTP_1588_CLOCK` to `imply PTP_1588_CLOCK`, "in order to break the hard dependency between the PTP clock subsystem and ethernet drivers capable of being clock providers." As a result it is possible to build PTP-capable Ethernet drivers without the PTP subsystem by deselecting PTP_1588_CLOCK. Drivers are required to handle the missing dependency gracefully.
Some PTP-capable Ethernet drivers (e.g., TI_CPSW) factor their PTP code out into separate drivers (e.g., TI_CPTS_MOD). The above commit also changed these PTP-specific drivers to `imply PTP_1588_CLOCK`, making it possible to build them without the PTP subsystem. But as Grygorii Strashko noted in [1]:
On Wed, Apr 22, 2020 at 02:16:11PM +0300, Grygorii Strashko wrote:
Another question is that CPTS completely nonfunctional in this case and it was never expected that somebody will even try to use/run such configuration (except for random build purposes).
In my view, enabling a PTP-specific driver without the PTP subsystem is a configuration error made possible by the above commit. Kconfig should not allow users to create a configuration with missing dependencies that results in "completely nonfunctional" drivers.
I audited all network drivers that call ptp_clock_register() but merely `imply PTP_1588_CLOCK` and found five PTP-specific drivers that are likely nonfunctional without PTP_1588_CLOCK:
NET_DSA_MV88E6XXX_PTP NET_DSA_SJA1105_PTP MACB_USE_HWSTAMP CAVIUM_PTP TI_CPTS_MOD
Note how these symbols all reference PTP or timestamping in their name; this is a clue that they depend on PTP_1588_CLOCK.
Change them from `imply PTP_1588_CLOCK` [2] to `depends on PTP_1588_CLOCK`. I'm not using `select PTP_1588_CLOCK` here because PTP_1588_CLOCK has its own dependencies, which `select` would not transitively apply.
Additionally, remove the `select NET_PTP_CLASSIFY` from CPTS_TI_MOD; PTP_1588_CLOCK already selects that.
[1]: https://lore.kernel.org/lkml/c04458ed-29ee-1797-3a11-7f3f560553e6@ti.com/
[2]: NET_DSA_SJA1105_PTP had never declared any type of dependency on PTP_1588_CLOCK (`imply` or otherwise); adding a `depends on PTP_1588_CLOCK` here seems appropriate.
Cc: Arnd Bergmann arnd@arndb.de Cc: Richard Cochran richardcochran@gmail.com Cc: Nicolas Pitre nico@fluxnic.net Cc: Grygorii Strashko grygorii.strashko@ti.com Cc: Geert Uytterhoeven geert@linux-m68k.org Fixes: d1cbfd771ce8 ("ptp_clock: Allow for it to be optional") Signed-off-by: Clay McClure clay@daemons.net Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/mv88e6xxx/Kconfig | 2 +- drivers/net/dsa/sja1105/Kconfig | 1 + drivers/net/ethernet/cadence/Kconfig | 2 +- drivers/net/ethernet/cavium/Kconfig | 2 +- drivers/net/ethernet/ti/Kconfig | 3 +-- 5 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/dsa/mv88e6xxx/Kconfig b/drivers/net/dsa/mv88e6xxx/Kconfig index 6435020d690dd..51185e4d7d15e 100644 --- a/drivers/net/dsa/mv88e6xxx/Kconfig +++ b/drivers/net/dsa/mv88e6xxx/Kconfig @@ -24,8 +24,8 @@ config NET_DSA_MV88E6XXX_PTP bool "PTP support for Marvell 88E6xxx" default n depends on NET_DSA_MV88E6XXX_GLOBAL2 + depends on PTP_1588_CLOCK imply NETWORK_PHY_TIMESTAMPING - imply PTP_1588_CLOCK help Say Y to enable PTP hardware timestamping on Marvell 88E6xxx switch chips that support it. diff --git a/drivers/net/dsa/sja1105/Kconfig b/drivers/net/dsa/sja1105/Kconfig index 0fe1ae173aa1a..68c3086af9af8 100644 --- a/drivers/net/dsa/sja1105/Kconfig +++ b/drivers/net/dsa/sja1105/Kconfig @@ -20,6 +20,7 @@ tristate "NXP SJA1105 Ethernet switch family support" config NET_DSA_SJA1105_PTP bool "Support for the PTP clock on the NXP SJA1105 Ethernet switch" depends on NET_DSA_SJA1105 + depends on PTP_1588_CLOCK help This enables support for timestamping and PTP clock manipulations in the SJA1105 DSA driver. diff --git a/drivers/net/ethernet/cadence/Kconfig b/drivers/net/ethernet/cadence/Kconfig index 53b50c24d9c95..2c4c12b03502d 100644 --- a/drivers/net/ethernet/cadence/Kconfig +++ b/drivers/net/ethernet/cadence/Kconfig @@ -35,8 +35,8 @@ config MACB config MACB_USE_HWSTAMP bool "Use IEEE 1588 hwstamp" depends on MACB + depends on PTP_1588_CLOCK default y - imply PTP_1588_CLOCK ---help--- Enable IEEE 1588 Precision Time Protocol (PTP) support for MACB.
diff --git a/drivers/net/ethernet/cavium/Kconfig b/drivers/net/ethernet/cavium/Kconfig index 6a700d34019e3..4520e7ee00fe1 100644 --- a/drivers/net/ethernet/cavium/Kconfig +++ b/drivers/net/ethernet/cavium/Kconfig @@ -54,7 +54,7 @@ config THUNDER_NIC_RGX config CAVIUM_PTP tristate "Cavium PTP coprocessor as PTP clock" depends on 64BIT && PCI - imply PTP_1588_CLOCK + depends on PTP_1588_CLOCK ---help--- This driver adds support for the Precision Time Protocol Clocks and Timestamping coprocessor (PTP) found on Cavium processors. diff --git a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig index bf98e0fa7d8be..cd6eda83e1f8c 100644 --- a/drivers/net/ethernet/ti/Kconfig +++ b/drivers/net/ethernet/ti/Kconfig @@ -89,9 +89,8 @@ config TI_CPTS config TI_CPTS_MOD tristate depends on TI_CPTS + depends on PTP_1588_CLOCK default y if TI_CPSW=y || TI_KEYSTONE_NETCP=y || TI_CPSW_SWITCHDEV=y - select NET_PTP_CLASSIFY - imply PTP_1588_CLOCK default m
config TI_KEYSTONE_NETCP