On Sun, 22 Apr 2012 16:49:53 +0100 Chris Wilson <chris at chris-wilson.co.uk> wrote: > On Fri, 20 Apr 2012 11:50:01 -0700, Ben Widawsky <ben at bwidawsk.net> > wrote: > > Chris' fix for my 32b breakage was incorrect. do_div returns a > > remainder. Go back to a divide macro which is more 32b friendly. > > > > Tested on x86-64. > > > > This has only been compile tested on 32b systems. > Doesn't compile on my 32-bit systems. > > Still does a 64-bit divide. This is weird. I don't understand what's broken exactly. It should be dividing an unsigned long long, which the 32b compiler should have no issue with. The macro itself expands to do_div which was your original fix. What is the error message you get? > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=48756 > > Cc: Chris Wilson <chris at chris-wilson.co.uk> > > Signed-off-by: Ben Widawsky <benjamin.widawsky at intel.com> > > --- > > drivers/gpu/drm/i915/i915_sysfs.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_sysfs.c > > b/drivers/gpu/drm/i915/i915_sysfs.c index f1b5108..bd6350b 100644 > > --- a/drivers/gpu/drm/i915/i915_sysfs.c > > +++ b/drivers/gpu/drm/i915/i915_sysfs.c > > @@ -39,8 +39,8 @@ static u32 calc_residency(struct drm_device *dev, > > const u32 reg) if (!intel_enable_rc6(dev)) > > return 0; > > > > - raw_time = I915_READ(reg) * 128ULL + 500; > > - return do_div(raw_time, 100000); > > + raw_time = I915_READ(reg) * 128ULL; > > + return DIV_ROUND_UP_ULL(raw_time, 1000) / 100; > return (u32)DIV_ROUND_UP_ULL(raw_time, 1000) / 100; > -Chris >
