From: Paulo Zanoni Subject: [PATCH] drm/i915: disable IPS while getting the pipe CRCs. Date: Fri, 17 Oct 2014 18:42:03 -0300 Message-ID: <1413582123-1962-1-git-send-email-przanoni@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qa0-f48.google.com (mail-qa0-f48.google.com [209.85.216.48]) by gabe.freedesktop.org (Postfix) with ESMTP id 30BFC6E397 for ; Fri, 17 Oct 2014 14:42:20 -0700 (PDT) Received: by mail-qa0-f48.google.com with SMTP id dc16so1122257qab.35 for ; Fri, 17 Oct 2014 14:42:19 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: intel-gfx@lists.freedesktop.org Cc: Paulo Zanoni List-Id: intel-gfx@lists.freedesktop.org From: Paulo Zanoni For some yet-undiscovered reason, when IPS gets enabled, the pipe CRC changes. Since hsw_enable_ips() doesn't really guarantees to enable IPS (it depends on package C-states), we can't really predict if IPS is enabled or disabled while running our CRC tests, so let's just completely disable IPS while pipe CRCs are being used. If we find a way to make IPS not change the pipe CRC result, we may want to fix IPS and then revert this patch. While this doesn't happen, let's merge this patch, so every IGT test relying on the CRCs can work on pipe A. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72864 Testcase: igt/kms_cursor_crc (and others) Signed-off-by: Paulo Zanoni --- drivers/gpu/drm/i915/i915_debugfs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index da4036d..cd1bc8f 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -3255,6 +3255,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe, { struct drm_i915_private *dev_priv = dev->dev_private; struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe]; + struct intel_crtc *crtc = to_intel_crtc(intel_get_crtc_for_pipe(dev, + pipe)); u32 val = 0; /* shut up gcc */ int ret; @@ -3290,6 +3292,14 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe, if (!pipe_crc->entries) return -ENOMEM; + /* + * When IPS gets enabled, the pipe CRC changes. Since IPS gets + * enabled and disabled dynamically based on package C states, + * user space can't make reliable use of the CRCs, so let's just + * completely disable it. + */ + hsw_disable_ips(crtc); + spin_lock_irq(&pipe_crc->lock); pipe_crc->head = 0; pipe_crc->tail = 0; @@ -3328,6 +3338,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe, vlv_undo_pipe_scramble_reset(dev, pipe); else if (IS_HASWELL(dev) && pipe == PIPE_A) hsw_undo_trans_edp_pipe_A_crc_wa(dev); + + hsw_enable_ips(crtc); } return 0; -- 2.1.1