From patchwork Wed Feb 6 11:10:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 2103581 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by patchwork2.kernel.org (Postfix) with ESMTP id D9899DF2A1 for ; Wed, 6 Feb 2013 11:11:32 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9317DE5C8B for ; Wed, 6 Feb 2013 03:11:32 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (smtp.fireflyinternet.com [109.228.6.236]) by gabe.freedesktop.org (Postfix) with ESMTP id EA36AE5CB8 for ; Wed, 6 Feb 2013 03:11:20 -0800 (PST) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.73.22; Received: from arrandale.alporthouse.com (unverified [78.156.73.22]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 128713244-1500050 for multiple; Wed, 06 Feb 2013 11:11:12 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 6 Feb 2013 11:10:21 +0000 Message-Id: <1360149028-13531-1-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 1.7.10.4 X-Originating-IP: 78.156.73.22 Subject: [Intel-gfx] [PATCH 1/8] drm/i915: Skip modifying PCH DREF if not changing clock sources X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org Modifying the clock sources (via the DREF control on the PCH) is a slow multi-stage process as we need to let the clocks stabilise between each stage. If we are not actually changing the clock sources, then we can return early. Signed-off-by: Chris Wilson Reviewed-by: Paulo Zanoni --- drivers/gpu/drm/i915/intel_display.c | 83 +++++++++++++++++++++++++--------- 1 file changed, 61 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index d75c6a0..f1dbd01 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4749,7 +4749,7 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) struct drm_i915_private *dev_priv = dev->dev_private; struct drm_mode_config *mode_config = &dev->mode_config; struct intel_encoder *encoder; - u32 temp; + u32 val, final; bool has_lvds = false; bool has_cpu_edp = false; bool has_pch_edp = false; @@ -4792,70 +4792,109 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) * PCH B stepping, previous chipset stepping should be * ignoring this setting. */ - temp = I915_READ(PCH_DREF_CONTROL); + val = I915_READ(PCH_DREF_CONTROL); + + /* As we must carefully and slowly disable/enable each source in turn, + * compute the final state we want first and check if we need to + * make any changes at all. + */ + final = val; + final &= ~DREF_NONSPREAD_SOURCE_MASK; + if (has_ck505) + final |= DREF_NONSPREAD_CK505_ENABLE; + else + final |= DREF_NONSPREAD_SOURCE_ENABLE; + + final &= ~DREF_SSC_SOURCE_MASK; + final &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + final &= ~DREF_SSC1_ENABLE; + + if (has_panel) { + final |= DREF_SSC_SOURCE_ENABLE; + + if (intel_panel_use_ssc(dev_priv) && can_ssc) + final |= DREF_SSC1_ENABLE; + + if (has_cpu_edp) { + if (intel_panel_use_ssc(dev_priv) && can_ssc) + final |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; + else + final |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; + } else + final |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + } else { + final |= DREF_SSC_SOURCE_DISABLE; + final |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + } + + if (final == val) + return; + /* Always enable nonspread source */ - temp &= ~DREF_NONSPREAD_SOURCE_MASK; + val &= ~DREF_NONSPREAD_SOURCE_MASK; if (has_ck505) - temp |= DREF_NONSPREAD_CK505_ENABLE; + val |= DREF_NONSPREAD_CK505_ENABLE; else - temp |= DREF_NONSPREAD_SOURCE_ENABLE; + val |= DREF_NONSPREAD_SOURCE_ENABLE; if (has_panel) { - temp &= ~DREF_SSC_SOURCE_MASK; - temp |= DREF_SSC_SOURCE_ENABLE; + val &= ~DREF_SSC_SOURCE_MASK; + val |= DREF_SSC_SOURCE_ENABLE; /* SSC must be turned on before enabling the CPU output */ if (intel_panel_use_ssc(dev_priv) && can_ssc) { DRM_DEBUG_KMS("Using SSC on panel\n"); - temp |= DREF_SSC1_ENABLE; + val |= DREF_SSC1_ENABLE; } else - temp &= ~DREF_SSC1_ENABLE; + val &= ~DREF_SSC1_ENABLE; /* Get SSC going before enabling the outputs */ - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); - temp &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; /* Enable CPU source on CPU attached eDP */ if (has_cpu_edp) { if (intel_panel_use_ssc(dev_priv) && can_ssc) { DRM_DEBUG_KMS("Using SSC on eDP\n"); - temp |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; + val |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; } else - temp |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; + val |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; } else - temp |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + val |= DREF_CPU_SOURCE_OUTPUT_DISABLE; - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); } else { DRM_DEBUG_KMS("Disabling SSC entirely\n"); - temp &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; /* Turn off CPU output */ - temp |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + val |= DREF_CPU_SOURCE_OUTPUT_DISABLE; - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); /* Turn off the SSC source */ - temp &= ~DREF_SSC_SOURCE_MASK; - temp |= DREF_SSC_SOURCE_DISABLE; + val &= ~DREF_SSC_SOURCE_MASK; + val |= DREF_SSC_SOURCE_DISABLE; /* Turn off SSC1 */ - temp &= ~ DREF_SSC1_ENABLE; + val &= ~ DREF_SSC1_ENABLE; - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); } + + BUG_ON(val != final); } /* Sequence to enable CLKOUT_DP for FDI usage and configure PCH FDI I/O. */