[Intel-gfx] [PATCH 04/12] drm/i915: Remove csr.state, csr_lock and related code

Daniel Vetter daniel.vetter at ffwll.ch
Thu Jul 9 13:04:40 PDT 2015


They don't serve a purpose any more after the preceding patches.

This removes two anti-patterns:
- Locking shouldn't be used to synchronize with async work (of any
  form, whether callbacks, workers or other threads). This is what the
  mutex_lock/unlock seems to have been for in intel_csr_load_program.
  Instead ordering should be ensured with the generic
  wait_for_completion()/complete(). Or more specific functions
  provided by the core kernel like e.g.
  flush_work()/cancel_work_sync() in the case of synchronizing with a
  work item.

- Don't invent your own completion like this code did with the
  (already removed) wait_for(csr_load_status_get()) pattern - it's
  really hard to get these right when you want them to be _really_
  correct (and be fast) in all cases. Furthermore it's easier to read
  code using the well-known primitives than new ones using
  non-standard names.

Cc: Animesh Manna <animesh.manna at intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c  |  1 -
 drivers/gpu/drm/i915/i915_drv.c  |  6 -----
 drivers/gpu/drm/i915/i915_drv.h  | 10 ---------
 drivers/gpu/drm/i915/intel_csr.c | 48 +---------------------------------------
 drivers/gpu/drm/i915/intel_drv.h |  3 ---
 5 files changed, 1 insertion(+), 67 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 6d3a7466a430..1d1a3bb51bf2 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -795,7 +795,6 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	spin_lock_init(&dev_priv->mmio_flip_lock);
 	mutex_init(&dev_priv->sb_lock);
 	mutex_init(&dev_priv->modeset_restore_lock);
-	mutex_init(&dev_priv->csr_lock);
 
 	intel_pm_setup(dev);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index b49697a9225f..bcc991f4cb3f 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1019,12 +1019,6 @@ static int skl_suspend_complete(struct drm_i915_private *dev_priv)
 {
 	/* Enabling DC6 is not a hard requirement to enter runtime D3 */
 
-	/*
-	 * This is to ensure that CSR isn't identified as loaded before
-	 * CSR-loading program is called during runtime-resume.
-	 */
-	intel_csr_load_status_set(dev_priv, FW_UNINITIALIZED);
-
 	skl_uninit_cdclk(dev_priv);
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 52d07fbd9cc8..9eaefd7ab82e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -734,12 +734,6 @@ struct intel_uncore {
 #define for_each_fw_domain(domain__, dev_priv__, i__) \
 	for_each_fw_domain_mask(domain__, FORCEWAKE_ALL, dev_priv__, i__)
 
-enum csr_state {
-	FW_UNINITIALIZED = 0,
-	FW_LOADED,
-	FW_FAILED
-};
-
 struct intel_csr {
 	const char *fw_path;
 	__be32 *dmc_payload;
@@ -747,7 +741,6 @@ struct intel_csr {
 	uint32_t mmio_count;
 	uint32_t mmioaddr[8];
 	uint32_t mmiodata[8];
-	enum csr_state state;
 };
 
 #define DEV_INFO_FOR_EACH_FLAG(func, sep) \
@@ -1698,9 +1691,6 @@ struct drm_i915_private {
 
 	struct intel_csr csr;
 
-	/* Display CSR-related protection */
-	struct mutex csr_lock;
-
 	struct intel_gmbus gmbus[GMBUS_NUM_PINS];
 
 	/** gmbus_mutex protects against concurrent usage of the single hw gmbus
diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
index 6362653d19af..a0fbce046ef0 100644
--- a/drivers/gpu/drm/i915/intel_csr.c
+++ b/drivers/gpu/drm/i915/intel_csr.c
@@ -184,40 +184,6 @@ static char intel_get_substepping(struct drm_device *dev)
 }
 
 /**
- * intel_csr_load_status_get() - to get firmware loading status.
- * @dev_priv: i915 device.
- *
- * This function helps to get the firmware loading status.
- *
- * Return: Firmware loading status.
- */
-enum csr_state intel_csr_load_status_get(struct drm_i915_private *dev_priv)
-{
-	enum csr_state state;
-
-	mutex_lock(&dev_priv->csr_lock);
-	state = dev_priv->csr.state;
-	mutex_unlock(&dev_priv->csr_lock);
-
-	return state;
-}
-
-/**
- * intel_csr_load_status_set() - help to set firmware loading status.
- * @dev_priv: i915 device.
- * @state: enumeration of firmware loading status.
- *
- * Set the firmware loading status.
- */
-void intel_csr_load_status_set(struct drm_i915_private *dev_priv,
-			enum csr_state state)
-{
-	mutex_lock(&dev_priv->csr_lock);
-	dev_priv->csr.state = state;
-	mutex_unlock(&dev_priv->csr_lock);
-}
-
-/**
  * intel_csr_load_program() - write the firmware from memory to register.
  * @dev: drm device.
  *
@@ -236,7 +202,6 @@ void intel_csr_load_program(struct drm_device *dev)
 		return;
 	}
 
-	mutex_lock(&dev_priv->csr_lock);
 	fw_size = dev_priv->csr.dmc_fw_size;
 	for (i = 0; i < fw_size; i++)
 		I915_WRITE(CSR_PROGRAM_BASE + i * 4,
@@ -246,9 +211,6 @@ void intel_csr_load_program(struct drm_device *dev)
 		I915_WRITE(dev_priv->csr.mmioaddr[i],
 			dev_priv->csr.mmiodata[i]);
 	}
-
-	dev_priv->csr.state = FW_LOADED;
-	mutex_unlock(&dev_priv->csr_lock);
 }
 
 static void finish_csr_load(const struct firmware *fw, void *context)
@@ -404,11 +366,6 @@ void intel_csr_ucode_init(struct drm_device *dev)
 
 	if (IS_SKYLAKE(dev))
 		csr->fw_path = I915_CSR_SKL;
-	else {
-		DRM_ERROR("Unexpected: no known CSR firmware for platform\n");
-		intel_csr_load_status_set(dev_priv, FW_FAILED);
-		return;
-	}
 
 	DRM_DEBUG_KMS("Loading %s\n", csr->fw_path);
 
@@ -423,10 +380,8 @@ void intel_csr_ucode_init(struct drm_device *dev)
 				&dev_priv->dev->pdev->dev,
 				GFP_KERNEL, dev_priv,
 				finish_csr_load);
-	if (ret) {
+	if (ret)
 		i915_firmware_load_error_print(csr->fw_path, ret);
-		intel_csr_load_status_set(dev_priv, FW_FAILED);
-	}
 }
 
 /**
@@ -443,6 +398,5 @@ void intel_csr_ucode_fini(struct drm_device *dev)
 	if (!HAS_CSR(dev))
 		return;
 
-	intel_csr_load_status_set(dev_priv, FW_FAILED);
 	kfree(dev_priv->csr.dmc_payload);
 }
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index ab585e734f99..094a223238eb 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1163,9 +1163,6 @@ u32 skl_plane_ctl_rotation(unsigned int rotation);
 
 /* intel_csr.c */
 void intel_csr_ucode_init(struct drm_device *dev);
-enum csr_state intel_csr_load_status_get(struct drm_i915_private *dev_priv);
-void intel_csr_load_status_set(struct drm_i915_private *dev_priv,
-					enum csr_state state);
 void intel_csr_load_program(struct drm_device *dev);
 void intel_csr_ucode_fini(struct drm_device *dev);
 
-- 
2.1.4



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