This is a note to let you know that I've just added the patch titled
net: Make PTP-specific drivers depend on PTP_1588_CLOCK
to the 5.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-make-ptp-specific-drivers-depend-on-ptp_1588_clo.patch
and it can be found in the queue-5.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit de35f6f92b03c5b9586bb7fd63b906045e12ee81
Author: Clay McClure <clay@xxxxxxxxxxx>
Date: Wed Apr 29 00:59:00 2020 -0700
net: Make PTP-specific drivers depend on PTP_1588_CLOCK
[ 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@xxxxxx/
[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@xxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Nicolas Pitre <nico@xxxxxxxxxxx>
Cc: Grygorii Strashko <grygorii.strashko@xxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Fixes: d1cbfd771ce8 ("ptp_clock: Allow for it to be optional")
Signed-off-by: Clay McClure <clay@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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
