From: Ben Widawsky Date: Thu, 13 Sep 2012 01:12:07 +0000 (-0700) Subject: drm/i915: Add setters for min/max frequency X-Git-Tag: omap-for-v3.7-rc1/fixes-cpufreq-signed~20^2~14^2~16 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=46ddf194776500e132693dd2c11b28a971070cc0;p=pandora-kernel.git drm/i915: Add setters for min/max frequency Provide a standardized sysfs interface for setting min, and max frequencies. The code which reads the limits were lifted from the debugfs files. As a brief explanation, the limits are similar to the CPU p-states. We have 3 states: RP0 - ie. max frequency RP1 - ie. "preferred min" frequency RPn - seriously lowest frequency Initially Daniel asked me to clamp the writes to supported values, but in conforming to the way the cpufreq drivers seem to work, instead return -EINVAL (noticed by Jesse in discussion). The values can be used by userspace wishing to control the limits of the GPU (see the CC list for people who care). v4: Make exceeding the soft limits return -EINVAL as well (Daniel) v3: bug fix (Ben) - was passing the MHz value to gen6_set_rps instead of the step value. To fix, deal only with step values by doing the divide at the top. v2: add the dropped mutex_unlock in error cases (Chris) EINVAL on both too min, or too max (Daniel) v2 Reviewed-by: Chris Wilson CC: Daniel Vetter Signed-off-by: Ben Widawsky Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed