From 0980a60fba7a9afa3259390e8af16b6ce486858a Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 26 Jul 2013 19:57:35 +0100 Subject: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI Otherwise we get flooded by the kernel warning us that we are doing long sequences of IO without serialisation. For example, WARNING: CPU: 0 PID: 11136 at drivers/gpu/drm/i915/intel_sideband.c:40 vlv_sideband_rw+0x48/0x1ef() Modules linked in: CPU: 0 PID: 11136 Comm: kworker/u2:0 Tainted: G W 3.11.0-rc2+ #4 Call Trace: [] ? warn_slowpath_common+0x63/0x78 [] ? vlv_sideband_rw+0x48/0x1ef [] ? warn_slowpath_null+0xf/0x13 [] ? vlv_sideband_rw+0x48/0x1ef [] ? vlv_dpio_write+0x1c/0x21 [] ? intel_dp_set_signal_levels+0x24a/0x385 [] ? intel_dp_complete_link_train+0x25/0x1d1 [] ? intel_dp_check_link_status+0xf7/0x106 [] ? i915_hotplug_work_func+0x17b/0x221 [] ? process_one_work+0x12e/0x210 [] ? worker_thread+0x116/0x1ad [] ? rescuer_thread+0x1cb/0x1cb [] ? kthread+0x67/0x6c [] ? ret_from_kernel_thread+0x1b/0x30 [] ? init_completion+0x18/0x18 v2: Retire the locking in vlv_crtc_enable() and do it close to the meat. Signed-off-by: Chris Wilson Reviewed-by: Jani Nikula [danvet: Squash in a s/mutex_lock/mutex_unlock/ fixup spotted by the 0 day kernel build/coccinelle and reported by Dan Carpenter.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 4 ---- drivers/gpu/drm/i915/intel_dp.c | 6 ++++++ drivers/gpu/drm/i915/intel_hdmi.c | 4 ++++ 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index dc7ad2a..9c59b42 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3652,8 +3652,6 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc) intel_crtc->active = true; intel_update_watermarks(dev); - mutex_lock(&dev_priv->dpio_lock); - for_each_encoder_on_crtc(dev, crtc, encoder) if (encoder->pre_pll_enable) encoder->pre_pll_enable(encoder); @@ -3678,8 +3676,6 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc) intel_crtc_update_cursor(crtc, true); intel_update_fbc(dev); - - mutex_unlock(&dev_priv->dpio_lock); } static void i9xx_crtc_enable(struct drm_crtc *crtc) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index e5eeec3..d96360d 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1727,6 +1727,7 @@ static void intel_pre_enable_dp(struct intel_encoder *encoder) int pipe = intel_crtc->pipe; u32 val; + mutex_lock(&dev_priv->dpio_lock); val = vlv_dpio_read(dev_priv, DPIO_DATA_LANE_A(port)); val = 0; if (pipe) @@ -1740,6 +1741,7 @@ static void intel_pre_enable_dp(struct intel_encoder *encoder) 0x00760018); vlv_dpio_write(dev_priv, DPIO_PCS_CLOCKBUF8(port), 0x00400888); + mutex_unlock(&dev_priv->dpio_lock); } } @@ -1754,6 +1756,7 @@ static void intel_dp_pre_pll_enable(struct intel_encoder *encoder) return; /* Program Tx lane resets to default */ + mutex_lock(&dev_priv->dpio_lock); vlv_dpio_write(dev_priv, DPIO_PCS_TX(port), DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET); @@ -1767,6 +1770,7 @@ static void intel_dp_pre_pll_enable(struct intel_encoder *encoder) vlv_dpio_write(dev_priv, DPIO_PCS_STAGGER1(port), 0x00750f00); vlv_dpio_write(dev_priv, DPIO_TX_CTL(port), 0x00001500); vlv_dpio_write(dev_priv, DPIO_TX_LANE(port), 0x40400000); + mutex_unlock(&dev_priv->dpio_lock); } /* @@ -1978,6 +1982,7 @@ static uint32_t intel_vlv_signal_levels(struct intel_dp *intel_dp) return 0; } + mutex_lock(&dev_priv->dpio_lock); vlv_dpio_write(dev_priv, DPIO_TX_OCALINIT(port), 0x00000000); vlv_dpio_write(dev_priv, DPIO_TX_SWING_CTL4(port), demph_reg_value); vlv_dpio_write(dev_priv, DPIO_TX_SWING_CTL2(port), @@ -1986,6 +1991,7 @@ static uint32_t intel_vlv_signal_levels(struct intel_dp *intel_dp) vlv_dpio_write(dev_priv, DPIO_PCS_STAGGER0(port), 0x00030000); vlv_dpio_write(dev_priv, DPIO_PCS_CTL_OVER1(port), preemph_reg_value); vlv_dpio_write(dev_priv, DPIO_TX_OCALINIT(port), 0x80000000); + mutex_unlock(&dev_priv->dpio_lock); return 0; } diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index c16fb34..847ff20 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -1019,6 +1019,7 @@ static void intel_hdmi_pre_enable(struct intel_encoder *encoder) return; /* Enable clock channels for this port */ + mutex_lock(&dev_priv->dpio_lock); val = vlv_dpio_read(dev_priv, DPIO_DATA_LANE_A(port)); val = 0; if (pipe) @@ -1049,6 +1050,7 @@ static void intel_hdmi_pre_enable(struct intel_encoder *encoder) 0x00760018); vlv_dpio_write(dev_priv, DPIO_PCS_CLOCKBUF8(port), 0x00400888); + mutex_unlock(&dev_priv->dpio_lock); } static void intel_hdmi_pre_pll_enable(struct intel_encoder *encoder) @@ -1062,6 +1064,7 @@ static void intel_hdmi_pre_pll_enable(struct intel_encoder *encoder) return; /* Program Tx lane resets to default */ + mutex_lock(&dev_priv->dpio_lock); vlv_dpio_write(dev_priv, DPIO_PCS_TX(port), DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET); @@ -1080,6 +1083,7 @@ static void intel_hdmi_pre_pll_enable(struct intel_encoder *encoder) 0x00002000); vlv_dpio_write(dev_priv, DPIO_TX_OCALINIT(port), DPIO_TX_OCALINIT_EN); + mutex_unlock(&dev_priv->dpio_lock); } static void intel_hdmi_post_disable(struct intel_encoder *encoder) -- 2.7.4