| Message ID | 20240909-can-rockchip_canfd-fix-64-bit-division-v1-1-2748d9422b00@pengutronix.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | can: rockchip_canfd: rkcanfd_timestamp_init(): fix 64 bit division on 32 bit platforms | expand |
On Mon, Sep 09, 2024 at 08:21:49AM +0200, Marc Kleine-Budde wrote: > On some 32-bit platforms (at least on parisc), the compiler generates > a call to __divdi3() from the u32 by 3 division in > rkcanfd_timestamp_init(), which results in the following linker > error: > > | ERROR: modpost: "__divdi3" [drivers/net/can/rockchip/rockchip_canfd.ko] undefined! > > As this code doesn't run in the hot path, a 64 bit by 32 bit division > is OK, even on 32 bit platforms. Use an explicit call to div_u64() to > fix linking. > > Reported-by: kernel test robot <lkp@intel.com> > Closes: https://lore.kernel.org/oe-kbuild-all/202409072304.lCQWyNLU-lkp@intel.com/ > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Reviewed-by: Simon Horman <horms@kernel.org>
diff --git a/drivers/net/can/rockchip/rockchip_canfd-timestamp.c b/drivers/net/can/rockchip/rockchip_canfd-timestamp.c index 81cccc5fd838..fb1a8f4e6217 100644 --- a/drivers/net/can/rockchip/rockchip_canfd-timestamp.c +++ b/drivers/net/can/rockchip/rockchip_canfd-timestamp.c @@ -71,7 +71,7 @@ void rkcanfd_timestamp_init(struct rkcanfd_priv *priv) max_cycles = div_u64(ULLONG_MAX, cc->mult); max_cycles = min(max_cycles, cc->mask); - work_delay_ns = clocksource_cyc2ns(max_cycles, cc->mult, cc->shift) / 3; + work_delay_ns = div_u64(clocksource_cyc2ns(max_cycles, cc->mult, cc->shift), 3); priv->work_delay_jiffies = nsecs_to_jiffies(work_delay_ns); INIT_DELAYED_WORK(&priv->timestamp, rkcanfd_timestamp_work);
On some 32-bit platforms (at least on parisc), the compiler generates a call to __divdi3() from the u32 by 3 division in rkcanfd_timestamp_init(), which results in the following linker error: | ERROR: modpost: "__divdi3" [drivers/net/can/rockchip/rockchip_canfd.ko] undefined! As this code doesn't run in the hot path, a 64 bit by 32 bit division is OK, even on 32 bit platforms. Use an explicit call to div_u64() to fix linking. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202409072304.lCQWyNLU-lkp@intel.com/ Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> --- drivers/net/can/rockchip/rockchip_canfd-timestamp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: c259acab839e57eab0318f32da4ae803a8d59397 change-id: 20240909-can-rockchip_canfd-fix-64-bit-division-5f579fddebc9 Best regards,