There is a 64-bit division in iwl_mvm_get_crosstimestamp_fw(), which
results in a link failure when building 32-bit architectures with clang:
ld.lld: error: undefined symbol: __udivdi3
>>> referenced by ptp.c
>>> drivers/net/wireless/intel/iwlwifi/mvm/ptp.o:(iwl_mvm_phc_get_crosstimestamp) in archive vmlinux.a
GCC has optimizations for division by a constant that clang does not
implement, so this issue is not visible when building with GCC.
Use the 64-bit division helper div_u64(), which takes a u64 dividend and
u32 divisor, which matches this situation and prevents the emission of a
libcall for the division.
Fixes: 21fb8da6eb ("wifi: iwlwifi: mvm: read synced time from firmware if supported")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Link: https://github.com/ClangBuiltLinux/linux/issues/1826
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Link: https://lore.kernel.org/6423173a.620a0220.3d5cc.6358@mx.google.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
iwl_mvm_get_sync_time() reads the gp2 from the device and then
reads the system clock. Since the two reads are not done atomically,
unexpected delays may happen between the two reads (e.g. context
switch) which make it inaccurate.
In order to improve the accuracy of the cross timestamp, call
iwl_mvm_get_sync_time() multiple times in a loop and take the
result in which the difference between the two clock is the smallest.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.d9e6f8f8998a.I569939ec4ddf0c6c64c112e7d0c30583f5509d9a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Implement the following PHC operations:
1. adjtime - for adding an offset to the PHC clock time.
2. adjfine - for adjusting the PHC clock frequency.
3. gettime64 - for getting the PHC clock time. This function returns
the time as adjusted by adjtime and adjfine.
The adjusted time will also be used for time sync frames timestamping.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.f59750deeee4.I110a7e3ac3c6d39d9dbe1fe77001e3f5bc3814eb@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If the firmware supports reading synced GP2/ATRB timestamps,
read the synced timestamps from firmware instead of reading the
GP2 register and the system time separately. Reading the synced
time from firmware should be more accurate.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.a6be5f0b5580.Idedb496a5943fa496143066ffbed08185a8c4582@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add support to enable/disable PHC clock. The PHC clock includes support
for fetching the cross timestamp i.e. a non-atomic snapshot of the current
time from the hardware (WiFi device) clock and system clock (wall-clock)
simultaneously.
Signed-off-by: Krishnanand Prabhu <krishnanand.prabhu@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.ae1d64f513b9.Ib3b6ad61c9fa2fc5908f1e0d6f59f4af6eec1a77@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
