Bug 1549

Summary: hwclock --systohc can take 25 seconds
Product: Busybox Reporter: Ivo Clarysse <ivo.clarysse>
Component: OtherAssignee: unassigned
Status: RESOLVED FIXED    
Severity: normal CC: busybox-cvs
Priority: P5    
Version: 1.16.x   
Target Milestone: ---   
Hardware: PC   
OS: Linux   
Host: GNU/Linux 2.6 x86 Target: GNU/Linux 2.4 ARM / i.MX21
Build: 1.16.1

Description Ivo Clarysse 2010-04-14 10:53:57 UTC 
Since busybox 1.6.0, "hwclock --systohc" takes 25 seconds to complete on a Freescale i.MX21 (an ARM-based SoC) running at 266MHz.

This is due to the ""2010-01-06 hwclock: fix sizeof bug (used it on pointer, not array); make --systohc exact" change introduced in busybox 1.16.0.

Changing TWEAK_USEC from 200 to 1000 brought this time down again to less than 0.1 second.

By default TWEAK_USEC appears to be tuned for a 2.2GHz Intel Core 2. It would appear that when building for a typical embedded device, busybox must be patched to have 'hwclock --systohc' complete in an acceptable timespan.
Comment 1 Ivo Clarysse 2010-04-14 10:56:48 UTC 
Correction: Since busybox 1.6.0 -> Since busybox 1.16.0