Re: [Intel-gfx] [PATCH] drm/i915: Fix GT frequency rounding

2015-11-16 Thread Jani Nikula
On Fri, 13 Nov 2015, Bob Paauwe wrote: > On Fri, 13 Nov 2015 19:29:41 +0200 > Mika Kuoppala wrote: > >> When we set and later readback a frequency value through >> sysfs interface, igt/pm_rpm assumes that we get same value back >> if it matches hw granularity. >> >> On bxt we have found out that

Re: [Intel-gfx] [PATCH] drm/i915: Fix GT frequency rounding

2015-11-13 Thread Bob Paauwe
On Fri, 13 Nov 2015 19:29:41 +0200 Mika Kuoppala wrote: > When we set and later readback a frequency value through > sysfs interface, igt/pm_rpm assumes that we get same value back > if it matches hw granularity. > > On bxt we have found out that this is not always the case. > Currently frequenc

Re: [Intel-gfx] [PATCH] drm/i915: Fix GT frequency rounding

2015-11-13 Thread Ville Syrjälä
On Fri, Nov 13, 2015 at 07:29:41PM +0200, Mika Kuoppala wrote: > When we set and later readback a frequency value through > sysfs interface, igt/pm_rpm assumes that we get same value back > if it matches hw granularity. > > On bxt we have found out that this is not always the case. > Currently fre

[Intel-gfx] [PATCH] drm/i915: Fix GT frequency rounding

2015-11-13 Thread Mika Kuoppala
When we set and later readback a frequency value through sysfs interface, igt/pm_rpm assumes that we get same value back if it matches hw granularity. On bxt we have found out that this is not always the case. Currently frequency - hw ratio - frequency conversions round down, with few exceptions o