From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120309190206.525065521@linuxfoundation.org> Date: Fri, 09 Mar 2012 11:02:54 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eugeni Dodonov , Kenneth Graunke , Jesse Barnes Subject: [ 52/95] drm/i915: gen7: implement rczunit workaround In-Reply-To: <20120309194424.GA2134@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eugeni Dodonov commit eae66b50c760233fad526edf4a0d327be17a055d upstream. This is yet another workaround related to clock gating which we need on Ivy Bridge. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41353 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44610 Tested-by: Eugeni Dodonov Signed-off-by: Eugeni Dodonov Signed-off-by: Kenneth Graunke Signed-off-by: Jesse Barnes Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_display.c | 5 +++++ 2 files changed, 6 insertions(+) --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3476,6 +3476,7 @@ #define GT_FIFO_NUM_RESERVED_ENTRIES 20 #define GEN6_UCGCTL2 0x9404 +# define GEN6_RCZUNIT_CLOCK_GATE_DISABLE (1 << 13) # define GEN6_RCPBUNIT_CLOCK_GATE_DISABLE (1 << 12) # define GEN6_RCCUNIT_CLOCK_GATE_DISABLE (1 << 11) --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8248,6 +8248,11 @@ static void ivybridge_init_clock_gating( I915_WRITE(WM2_LP_ILK, 0); I915_WRITE(WM1_LP_ILK, 0); + /* According to the spec, bit 13 (RCZUNIT) must be set on IVB. + * This implements the WaDisableRCZUnitClockGating workaround. + */ + I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE); + I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE); for_each_pipe(pipe) {