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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2016-09-20 19:25:58 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-22 02:18:33 -0400 |
| commit | efee95f42b5dddedcaff0a0eaa44e170fc7522e8 (patch) | |
| tree | e5d83b374d57e1bced53af0345db98f0f6cd4373 /include/linux/ptp_clock_kernel.h | |
| parent | d270f76c2d6ee3d96cfb1affb78a3d536e0b8fd6 (diff) | |
| download | linux-efee95f42b5dddedcaff0a0eaa44e170fc7522e8.tar.gz linux-efee95f42b5dddedcaff0a0eaa44e170fc7522e8.tar.bz2 linux-efee95f42b5dddedcaff0a0eaa44e170fc7522e8.zip | |
ptp_clock: future-proofing drivers against PTP subsystem becoming optional
Drivers must be ready to accept NULL from ptp_clock_register() if the
PTP clock subsystem is configured out.
This patch documents that and ensures that all drivers cope well
with a NULL return.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Eugenia Emantayev <eugenia@mellanox.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/ptp_clock_kernel.h')
| -rw-r--r-- | include/linux/ptp_clock_kernel.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h index 6b15e168148a..5ad54fc66cf0 100644 --- a/include/linux/ptp_clock_kernel.h +++ b/include/linux/ptp_clock_kernel.h @@ -127,6 +127,11 @@ struct ptp_clock; * * @info: Structure describing the new clock. * @parent: Pointer to the parent device of the new clock. + * + * Returns a valid pointer on success or PTR_ERR on failure. If PHC + * support is missing at the configuration level, this function + * returns NULL, and drivers are expected to gracefully handle that + * case separately. */ extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, |