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* [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
@ 2013-07-26 16:17 Chris Wilson
  2013-07-26 16:46 ` Daniel Vetter
  2013-07-26 18:57 ` Chris Wilson
  0 siblings, 2 replies; 8+ messages in thread
From: Chris Wilson @ 2013-07-26 16:17 UTC (permalink / raw)
  To: intel-gfx

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:
  [<c2028564>] ?  warn_slowpath_common+0x63/0x78
  [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
  [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
  [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
  [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
  [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
  [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
  [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
  [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
  [<c203a204>] ?  process_one_work+0x12e/0x210
  [<c203a5e4>] ?  worker_thread+0x116/0x1ad
  [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
  [<c203d8f5>] ?  kthread+0x67/0x6c
  [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
  [<c203d88e>] ?  init_completion+0x18/0x18

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_dp.c   | 6 ++++++
 drivers/gpu/drm/i915/intel_hdmi.c | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 4a7ba5e..2a455b8 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1719,6 +1719,7 @@ 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)
@@ -1732,6 +1733,7 @@ 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);
 	}
 }
 
@@ -1746,6 +1748,7 @@ 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);
@@ -1759,6 +1762,7 @@ 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);
 }
 
 /*
@@ -1970,6 +1974,7 @@ 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),
@@ -1978,6 +1983,7 @@ 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 044d11d..5fa3035 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1033,6 +1033,7 @@ 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)
@@ -1063,6 +1064,7 @@ 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)
@@ -1076,6 +1078,7 @@ 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);
@@ -1094,6 +1097,7 @@ 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_lock(&dev_priv->dpio_lock);
 }
 
 static void intel_hdmi_post_disable(struct intel_encoder *encoder)
-- 
1.8.3.2

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-26 16:17 [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI Chris Wilson
@ 2013-07-26 16:46 ` Daniel Vetter
  2013-07-26 17:11   ` Chris Wilson
  2013-07-26 18:57 ` Chris Wilson
  1 sibling, 1 reply; 8+ messages in thread
From: Daniel Vetter @ 2013-07-26 16:46 UTC (permalink / raw)
  To: Chris Wilson; +Cc: intel-gfx

On Fri, Jul 26, 2013 at 6:17 PM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> 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:
>   [<c2028564>] ?  warn_slowpath_common+0x63/0x78
>   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
>   [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
>   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
>   [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
>   [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
>   [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
>   [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
>   [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
>   [<c203a204>] ?  process_one_work+0x12e/0x210
>   [<c203a5e4>] ?  worker_thread+0x116/0x1ad
>   [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
>   [<c203d8f5>] ?  kthread+0x67/0x6c
>   [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
>   [<c203d88e>] ?  init_completion+0x18/0x18
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

The problem here is that Jesse was lazy and grabs the lock in
vlv_crtc_enable, so I think your code here will deadlock. But I agree
that grabbing the lock where we actually frob the sideband is what we
want ...
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_dp.c   | 6 ++++++
>  drivers/gpu/drm/i915/intel_hdmi.c | 4 ++++
>  2 files changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 4a7ba5e..2a455b8 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1719,6 +1719,7 @@ 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)
> @@ -1732,6 +1733,7 @@ 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);
>         }
>  }
>
> @@ -1746,6 +1748,7 @@ 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);
> @@ -1759,6 +1762,7 @@ 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);
>  }
>
>  /*
> @@ -1970,6 +1974,7 @@ 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),
> @@ -1978,6 +1983,7 @@ 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 044d11d..5fa3035 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1033,6 +1033,7 @@ 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)
> @@ -1063,6 +1064,7 @@ 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)
> @@ -1076,6 +1078,7 @@ 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);
> @@ -1094,6 +1097,7 @@ 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_lock(&dev_priv->dpio_lock);
>  }
>
>  static void intel_hdmi_post_disable(struct intel_encoder *encoder)
> --
> 1.8.3.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx



--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-26 16:46 ` Daniel Vetter
@ 2013-07-26 17:11   ` Chris Wilson
  2013-07-26 17:43     ` Daniel Vetter
  0 siblings, 1 reply; 8+ messages in thread
From: Chris Wilson @ 2013-07-26 17:11 UTC (permalink / raw)
  To: Daniel Vetter; +Cc: intel-gfx

On Fri, Jul 26, 2013 at 06:46:43PM +0200, Daniel Vetter wrote:
> On Fri, Jul 26, 2013 at 6:17 PM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > 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:
> >   [<c2028564>] ?  warn_slowpath_common+0x63/0x78
> >   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
> >   [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
> >   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
> >   [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
> >   [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
> >   [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
> >   [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
> >   [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
> >   [<c203a204>] ?  process_one_work+0x12e/0x210
> >   [<c203a5e4>] ?  worker_thread+0x116/0x1ad
> >   [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
> >   [<c203d8f5>] ?  kthread+0x67/0x6c
> >   [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
> >   [<c203d88e>] ?  init_completion+0x18/0x18
> >
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> 
> The problem here is that Jesse was lazy and grabs the lock in
> vlv_crtc_enable, so I think your code here will deadlock. But I agree
> that grabbing the lock where we actually frob the sideband is what we
> want ...

Looks like vlv_crtc_enable() is the only place that takes the lock around
callbacks, so I propose dropping the locking in that function (and
scoping it around the sideband sequences as above).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-26 17:11   ` Chris Wilson
@ 2013-07-26 17:43     ` Daniel Vetter
  0 siblings, 0 replies; 8+ messages in thread
From: Daniel Vetter @ 2013-07-26 17:43 UTC (permalink / raw)
  To: Chris Wilson, Daniel Vetter, intel-gfx

On Fri, Jul 26, 2013 at 7:11 PM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
>> The problem here is that Jesse was lazy and grabs the lock in
>> vlv_crtc_enable, so I think your code here will deadlock. But I agree
>> that grabbing the lock where we actually frob the sideband is what we
>> want ...
>
> Looks like vlv_crtc_enable() is the only place that takes the lock around
> callbacks, so I propose dropping the locking in that function (and
> scoping it around the sideband sequences as above).

Yeah, I think moving the locking into callbacks/lower-level functions
is the right approach.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-26 16:17 [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI Chris Wilson
  2013-07-26 16:46 ` Daniel Vetter
@ 2013-07-26 18:57 ` Chris Wilson
  2013-07-29 13:20   ` Jani Nikula
  1 sibling, 1 reply; 8+ messages in thread
From: Chris Wilson @ 2013-07-26 18:57 UTC (permalink / raw)
  To: intel-gfx

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:
  [<c2028564>] ?  warn_slowpath_common+0x63/0x78
  [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
  [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
  [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
  [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
  [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
  [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
  [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
  [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
  [<c203a204>] ?  process_one_work+0x12e/0x210
  [<c203a5e4>] ?  worker_thread+0x116/0x1ad
  [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
  [<c203d8f5>] ?  kthread+0x67/0x6c
  [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
  [<c203d88e>] ?  init_completion+0x18/0x18

v2: Retire the locking in vlv_crtc_enable() and do it close to the meat.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 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 b3389d7..6bb9017 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3653,8 +3653,6 @@ 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);
@@ -3679,8 +3677,6 @@ 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 4a7ba5e..2a455b8 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1719,6 +1719,7 @@ 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)
@@ -1732,6 +1733,7 @@ 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);
 	}
 }
 
@@ -1746,6 +1748,7 @@ 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);
@@ -1759,6 +1762,7 @@ 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);
 }
 
 /*
@@ -1970,6 +1974,7 @@ 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),
@@ -1978,6 +1983,7 @@ 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 044d11d..5fa3035 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1033,6 +1033,7 @@ 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)
@@ -1063,6 +1064,7 @@ 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)
@@ -1076,6 +1078,7 @@ 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);
@@ -1094,6 +1097,7 @@ 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_lock(&dev_priv->dpio_lock);
 }
 
 static void intel_hdmi_post_disable(struct intel_encoder *encoder)
-- 
1.8.3.2

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-26 18:57 ` Chris Wilson
@ 2013-07-29 13:20   ` Jani Nikula
  2013-07-29 14:50     ` Chris Wilson
  0 siblings, 1 reply; 8+ messages in thread
From: Jani Nikula @ 2013-07-29 13:20 UTC (permalink / raw)
  To: Chris Wilson, intel-gfx

On Fri, 26 Jul 2013, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> 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:
>   [<c2028564>] ?  warn_slowpath_common+0x63/0x78
>   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
>   [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
>   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
>   [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
>   [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
>   [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
>   [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
>   [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
>   [<c203a204>] ?  process_one_work+0x12e/0x210
>   [<c203a5e4>] ?  worker_thread+0x116/0x1ad
>   [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
>   [<c203d8f5>] ?  kthread+0x67/0x6c
>   [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
>   [<c203d88e>] ?  init_completion+0x18/0x18
>
> v2: Retire the locking in vlv_crtc_enable() and do it close to the
> meat.

Grumble about throwing the fix and the refactoring together for no real
reason, and having a slightly misleading subject. But since we have the
warnings in place, the patch is small, and the end result is what we
want, I'll let it pass. Just this once. ;)

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
>  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 b3389d7..6bb9017 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3653,8 +3653,6 @@ 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);
> @@ -3679,8 +3677,6 @@ 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 4a7ba5e..2a455b8 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1719,6 +1719,7 @@ 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)
> @@ -1732,6 +1733,7 @@ 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);
>  	}
>  }
>  
> @@ -1746,6 +1748,7 @@ 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);
> @@ -1759,6 +1762,7 @@ 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);
>  }
>  
>  /*
> @@ -1970,6 +1974,7 @@ 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),
> @@ -1978,6 +1983,7 @@ 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 044d11d..5fa3035 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1033,6 +1033,7 @@ 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)
> @@ -1063,6 +1064,7 @@ 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)
> @@ -1076,6 +1078,7 @@ 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);
> @@ -1094,6 +1097,7 @@ 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_lock(&dev_priv->dpio_lock);
>  }
>  
>  static void intel_hdmi_post_disable(struct intel_encoder *encoder)
> -- 
> 1.8.3.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Technology Center

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-29 13:20   ` Jani Nikula
@ 2013-07-29 14:50     ` Chris Wilson
  2013-08-05  5:35       ` Daniel Vetter
  0 siblings, 1 reply; 8+ messages in thread
From: Chris Wilson @ 2013-07-29 14:50 UTC (permalink / raw)
  To: Jani Nikula; +Cc: intel-gfx

On Mon, Jul 29, 2013 at 04:20:28PM +0300, Jani Nikula wrote:
> On Fri, 26 Jul 2013, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > 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:
> >   [<c2028564>] ?  warn_slowpath_common+0x63/0x78
> >   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
> >   [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
> >   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
> >   [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
> >   [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
> >   [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
> >   [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
> >   [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
> >   [<c203a204>] ?  process_one_work+0x12e/0x210
> >   [<c203a5e4>] ?  worker_thread+0x116/0x1ad
> >   [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
> >   [<c203d8f5>] ?  kthread+0x67/0x6c
> >   [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
> >   [<c203d88e>] ?  init_completion+0x18/0x18
> >
> > v2: Retire the locking in vlv_crtc_enable() and do it close to the
> > meat.
> 
> Grumble about throwing the fix and the refactoring together for no real
> reason, and having a slightly misleading subject. But since we have the
> warnings in place, the patch is small, and the end result is what we
> want, I'll let it pass. Just this once. ;)

Meh, easier than working which paths were covered by the current locking
scheme and which weren't - which I suppect conflict anyway. The
intention was just to do as the subject said, but then I had to fix the
deadlock presented by the patch...
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI
  2013-07-29 14:50     ` Chris Wilson
@ 2013-08-05  5:35       ` Daniel Vetter
  0 siblings, 0 replies; 8+ messages in thread
From: Daniel Vetter @ 2013-08-05  5:35 UTC (permalink / raw)
  To: Chris Wilson, Jani Nikula, intel-gfx

On Mon, Jul 29, 2013 at 03:50:14PM +0100, Chris Wilson wrote:
> On Mon, Jul 29, 2013 at 04:20:28PM +0300, Jani Nikula wrote:
> > On Fri, 26 Jul 2013, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > > 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:
> > >   [<c2028564>] ?  warn_slowpath_common+0x63/0x78
> > >   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
> > >   [<c20285dd>] ?  warn_slowpath_null+0xf/0x13
> > >   [<c227ad43>] ?  vlv_sideband_rw+0x48/0x1ef
> > >   [<c227b060>] ?  vlv_dpio_write+0x1c/0x21
> > >   [<c2262b3b>] ?  intel_dp_set_signal_levels+0x24a/0x385
> > >   [<c2264909>] ?  intel_dp_complete_link_train+0x25/0x1d1
> > >   [<c2264c55>] ?  intel_dp_check_link_status+0xf7/0x106
> > >   [<c2238ced>] ?  i915_hotplug_work_func+0x17b/0x221
> > >   [<c203a204>] ?  process_one_work+0x12e/0x210
> > >   [<c203a5e4>] ?  worker_thread+0x116/0x1ad
> > >   [<c203a4ce>] ?  rescuer_thread+0x1cb/0x1cb
> > >   [<c203d8f5>] ?  kthread+0x67/0x6c
> > >   [<c2457ebb>] ?  ret_from_kernel_thread+0x1b/0x30
> > >   [<c203d88e>] ?  init_completion+0x18/0x18
> > >
> > > v2: Retire the locking in vlv_crtc_enable() and do it close to the
> > > meat.
> > 
> > Grumble about throwing the fix and the refactoring together for no real
> > reason, and having a slightly misleading subject. But since we have the
> > warnings in place, the patch is small, and the end result is what we
> > want, I'll let it pass. Just this once. ;)
> 
> Meh, easier than working which paths were covered by the current locking
> scheme and which weren't - which I suppect conflict anyway. The
> intention was just to do as the subject said, but then I had to fix the
> deadlock presented by the patch...

Queued for -next, thanks for the patch. And I agree that in this case
splitting stuff further is just more awkward ...
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2013-08-05  5:35 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-07-26 16:17 [PATCH] drm/i915: Acquire dpio_lock for VLV sideband programming in DP/HDMI Chris Wilson
2013-07-26 16:46 ` Daniel Vetter
2013-07-26 17:11   ` Chris Wilson
2013-07-26 17:43     ` Daniel Vetter
2013-07-26 18:57 ` Chris Wilson
2013-07-29 13:20   ` Jani Nikula
2013-07-29 14:50     ` Chris Wilson
2013-08-05  5:35       ` Daniel Vetter

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