From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paulo Zanoni Subject: [PATCH 13/14] drm/i915: add some barriers when changing DIPs Date: Mon, 28 May 2012 16:43:00 -0300 Message-ID: <1338234182-5021-14-git-send-email-przanoni@gmail.com> References: <1338234182-5021-1-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-vb0-f49.google.com (mail-vb0-f49.google.com [209.85.212.49]) by gabe.freedesktop.org (Postfix) with ESMTP id EEC849ED9F for ; Mon, 28 May 2012 12:43:41 -0700 (PDT) Received: by mail-vb0-f49.google.com with SMTP id fo1so2456625vbb.36 for ; Mon, 28 May 2012 12:43:41 -0700 (PDT) In-Reply-To: <1338234182-5021-1-git-send-email-przanoni@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org Cc: Paulo Zanoni List-Id: intel-gfx@lists.freedesktop.org From: Paulo Zanoni On IVB and older, we basically have two registers: the control and the data register. We write a few consecutitve times to the control register, and we need these writes to arrive exactly in the specified order. Also, when we're changing the data register, we need to guarantee that anything written to the control register already arrived (since changing the control register can change where the data register points to). Also, we need to make sure all the writes to the data register happen exactly in the specified order, and we also *can't* read the data register during this process, since reading and/or writing it will change the place it points to. So invoke the "better safe than sorry" rule and just be careful and put barriers everywhere :) On HSW we still have a control register that we write many times, but we have many data registers. Demanded-by: Chris Wilson Signed-off-by: Paulo Zanoni --- drivers/gpu/drm/i915/intel_hdmi.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index d0a466a..f61af21 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -133,16 +133,19 @@ static void g4x_write_infoframe(struct drm_encoder *encoder, I915_WRITE(VIDEO_DIP_CTL, val); + mmiowb(); for (i = 0; i < len; i += 4) { I915_WRITE(VIDEO_DIP_DATA, *data); data++; } + mmiowb(); val |= g4x_infoframe_enable(frame); val &= ~VIDEO_DIP_FREQ_MASK; val |= VIDEO_DIP_FREQ_VSYNC; I915_WRITE(VIDEO_DIP_CTL, val); + POSTING_READ(VIDEO_DIP_CTL); } static void ibx_write_infoframe(struct drm_encoder *encoder, @@ -165,16 +168,19 @@ static void ibx_write_infoframe(struct drm_encoder *encoder, I915_WRITE(reg, val); + mmiowb(); for (i = 0; i < len; i += 4) { I915_WRITE(TVIDEO_DIP_DATA(intel_crtc->pipe), *data); data++; } + mmiowb(); val |= g4x_infoframe_enable(frame); val &= ~VIDEO_DIP_FREQ_MASK; val |= VIDEO_DIP_FREQ_VSYNC; I915_WRITE(reg, val); + POSTING_READ(reg); } static void cpt_write_infoframe(struct drm_encoder *encoder, @@ -200,16 +206,19 @@ static void cpt_write_infoframe(struct drm_encoder *encoder, I915_WRITE(reg, val); + mmiowb(); for (i = 0; i < len; i += 4) { I915_WRITE(TVIDEO_DIP_DATA(intel_crtc->pipe), *data); data++; } + mmiowb(); val |= g4x_infoframe_enable(frame); val &= ~VIDEO_DIP_FREQ_MASK; val |= VIDEO_DIP_FREQ_VSYNC; I915_WRITE(reg, val); + POSTING_READ(reg); } static void vlv_write_infoframe(struct drm_encoder *encoder, @@ -232,16 +241,19 @@ static void vlv_write_infoframe(struct drm_encoder *encoder, I915_WRITE(reg, val); + mmiowb(); for (i = 0; i < len; i += 4) { I915_WRITE(VLV_TVIDEO_DIP_DATA(intel_crtc->pipe), *data); data++; } + mmiowb(); val |= g4x_infoframe_enable(frame); val &= ~VIDEO_DIP_FREQ_MASK; val |= VIDEO_DIP_FREQ_VSYNC; I915_WRITE(reg, val); + POSTING_READ(reg); } static void hsw_write_infoframe(struct drm_encoder *encoder, @@ -262,13 +274,16 @@ static void hsw_write_infoframe(struct drm_encoder *encoder, val &= ~hsw_infoframe_enable(frame); I915_WRITE(ctl_reg, val); + mmiowb(); for (i = 0; i < len; i += 4) { I915_WRITE(data_reg + i, *data); data++; } + mmiowb(); val |= hsw_infoframe_enable(frame); I915_WRITE(ctl_reg, val); + POSTING_READ(ctl_reg); } static void intel_set_infoframe(struct drm_encoder *encoder, @@ -335,6 +350,7 @@ static void g4x_set_infoframes(struct drm_encoder *encoder, return; val &= ~VIDEO_DIP_ENABLE; I915_WRITE(reg, val); + POSTING_READ(reg); return; } @@ -353,6 +369,7 @@ static void g4x_set_infoframes(struct drm_encoder *encoder, if (val & VIDEO_DIP_ENABLE) { val &= ~VIDEO_DIP_ENABLE; I915_WRITE(reg, val); + POSTING_READ(reg); } val &= ~VIDEO_DIP_PORT_MASK; val |= port; @@ -362,6 +379,7 @@ static void g4x_set_infoframes(struct drm_encoder *encoder, val &= ~VIDEO_DIP_ENABLE_VENDOR; I915_WRITE(reg, val); + POSTING_READ(reg); intel_hdmi_set_avi_infoframe(encoder, adjusted_mode); intel_hdmi_set_spd_infoframe(encoder); @@ -385,6 +403,7 @@ static void ibx_set_infoframes(struct drm_encoder *encoder, return; val &= ~VIDEO_DIP_ENABLE; I915_WRITE(reg, val); + POSTING_READ(reg); return; } @@ -406,6 +425,7 @@ static void ibx_set_infoframes(struct drm_encoder *encoder, if (val & VIDEO_DIP_ENABLE) { val &= ~VIDEO_DIP_ENABLE; I915_WRITE(reg, val); + POSTING_READ(reg); } val &= ~VIDEO_DIP_PORT_MASK; val |= port; @@ -416,6 +436,7 @@ static void ibx_set_infoframes(struct drm_encoder *encoder, VIDEO_DIP_ENABLE_GCP); I915_WRITE(reg, val); + POSTING_READ(reg); intel_hdmi_set_avi_infoframe(encoder, adjusted_mode); intel_hdmi_set_spd_infoframe(encoder); @@ -438,6 +459,7 @@ static void cpt_set_infoframes(struct drm_encoder *encoder, return; val &= ~(VIDEO_DIP_ENABLE | VIDEO_DIP_ENABLE_AVI); I915_WRITE(reg, val); + POSTING_READ(reg); return; } @@ -447,6 +469,7 @@ static void cpt_set_infoframes(struct drm_encoder *encoder, VIDEO_DIP_ENABLE_GCP); I915_WRITE(reg, val); + POSTING_READ(reg); intel_hdmi_set_avi_infoframe(encoder, adjusted_mode); intel_hdmi_set_spd_infoframe(encoder); @@ -469,6 +492,7 @@ static void vlv_set_infoframes(struct drm_encoder *encoder, return; val &= ~VIDEO_DIP_ENABLE; I915_WRITE(reg, val); + POSTING_READ(reg); return; } @@ -477,6 +501,7 @@ static void vlv_set_infoframes(struct drm_encoder *encoder, VIDEO_DIP_ENABLE_GCP); I915_WRITE(reg, val); + POSTING_READ(reg); intel_hdmi_set_avi_infoframe(encoder, adjusted_mode); intel_hdmi_set_spd_infoframe(encoder); @@ -493,6 +518,7 @@ static void hsw_set_infoframes(struct drm_encoder *encoder, if (!intel_hdmi->has_hdmi_sink) { I915_WRITE(reg, 0); + POSTING_READ(reg); return; } @@ -500,6 +526,7 @@ static void hsw_set_infoframes(struct drm_encoder *encoder, VIDEO_DIP_ENABLE_VS_HSW | VIDEO_DIP_ENABLE_GMP_HSW); I915_WRITE(reg, val); + POSTING_READ(reg); intel_hdmi_set_avi_infoframe(encoder, adjusted_mode); intel_hdmi_set_spd_infoframe(encoder); -- 1.7.10