On Mon, Oct 07, 2013 at 05:15:48PM -0300, Rodrigo Vivi wrote: > From: Ben Widawsky <benjamin.widawsky@xxxxxxxxx> > > The policy's max frequency is not equal to the CPU's max frequency. The > ring frequency is derived from the CPU frequency, and not the policy > frequency. > > One example of how this may differ through sysfs. If the sysfs max > frequency is modified, that will be used for the max ring frequency > calculation. > (/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq). As far as I > know, no current governor uses anything but max as the default, but in > theory, they could. Similarly distributions might set policy as part of > their init process. > > It's ideal to use the real frequency because when we're currently scaled > up on the GPU. In this case we likely want to race to idle, and using a > less than max ring frequency is non-optimal for this situation. > > AFAIK, this patch should have no impact on a majority of people. > > This behavior hasn't been changed since it was first introduced: > commit 23b2f8bb92feb83127679c53633def32d3108e70 > Author: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> > Date: Tue Jun 28 13:04:16 2011 -0700 > > drm/i915: load a ring frequency scaling table v3 > > CC: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> > Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx> > Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Queued for -next, thanks for the patch. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
