From 6cf882d9aa9e8f1f2d63182e179ac4b2e59c00db Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 29 Mar 2023 10:32:46 -0700 Subject: [PATCH] wifi: iwlwifi: mvm: Use 64-bit division helper in iwl_mvm_get_crosstimestamp_fw() 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: 21fb8da6ebe4 ("wifi: iwlwifi: mvm: read synced time from firmware if supported") Reported-by: Arnd Bergmann Link: https://github.com/ClangBuiltLinux/linux/issues/1826 Reported-by: "kernelci.org bot" Link: https://lore.kernel.org/6423173a.620a0220.3d5cc.6358@mx.google.com/ Signed-off-by: Nathan Chancellor Signed-off-by: Johannes Berg --- drivers/net/wireless/intel/iwlwifi/mvm/ptp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c b/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c index 5c2bfc8ed88d..e89259de6f4c 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c @@ -116,7 +116,7 @@ iwl_mvm_get_crosstimestamp_fw(struct iwl_mvm *mvm, u32 *gp2, u64 *sys_time) gp2_10ns = (u64)le32_to_cpu(resp->gp2_timestamp_hi) << 32 | le32_to_cpu(resp->gp2_timestamp_lo); - *gp2 = gp2_10ns / 100; + *gp2 = div_u64(gp2_10ns, 100); *sys_time = (u64)le32_to_cpu(resp->platform_timestamp_hi) << 32 | le32_to_cpu(resp->platform_timestamp_lo);