Re: [PATCH drm/hisilicon v2 1/4] drm/hisilicon: Assgin local variable to drm_device

Tue, 01 Dec 2020 05:08:26 -0800 



在 2020/12/1 20:36, Thomas Zimmermann 写道:

Hi

Am 01.12.20 um 13:26 schrieb tiantao (H):



在 2020/12/1 20:17, Thomas Zimmermann 写道:

Hi

Am 01.12.20 um 12:55 schrieb Tian Tao:

Assign local variable to struct drm_device *dev because they are
used multiple times within a function.

Signed-off-by: Tian Tao <tiant...@hisilicon.com>
---
  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_de.c   |  2 +-

  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c  | 30 
++++++++++++------------

  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h  |  2 +-
  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c |  2 +-
  drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c      |  8 ++++---
  5 files changed, 23 insertions(+), 21 deletions(-)


diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_de.c 
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_de.c

index ea962ac..096eea9 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_de.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_de.c

@@ -499,7 +499,7 @@ static const struct drm_crtc_helper_funcs 
hibmc_crtc_helper_funcs = {

  int hibmc_de_init(struct hibmc_drm_private *priv)
  {
-    struct drm_device *dev = priv->dev;
+    struct drm_device *dev = &priv->dev;
      struct drm_crtc *crtc = &priv->crtc;
      struct drm_plane *plane = &priv->primary_plane;
      int ret;

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c 
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c

index d845657..dd9fadc 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
@@ -79,31 +79,32 @@ static const struct dev_pm_ops hibmc_pm_ops = {
  static int hibmc_kms_init(struct hibmc_drm_private *priv)
  {
+    struct drm_device *dev = &priv->dev;
      int ret;
-    drm_mode_config_init(priv->dev);
+    drm_mode_config_init(dev);
      priv->mode_config_initialized = true;
-    priv->dev->mode_config.min_width = 0;
-    priv->dev->mode_config.min_height = 0;
-    priv->dev->mode_config.max_width = 1920;
-    priv->dev->mode_config.max_height = 1200;
+    dev->mode_config.min_width = 0;
+    dev->mode_config.min_height = 0;
+    dev->mode_config.max_width = 1920;
+    dev->mode_config.max_height = 1200;
-    priv->dev->mode_config.fb_base = priv->fb_base;
-    priv->dev->mode_config.preferred_depth = 32;
-    priv->dev->mode_config.prefer_shadow = 1;
+    dev->mode_config.fb_base = priv->fb_base;
+    dev->mode_config.preferred_depth = 32;
+    dev->mode_config.prefer_shadow = 1;
-    priv->dev->mode_config.funcs = (void *)&hibmc_mode_funcs;
+    dev->mode_config.funcs = (void *)&hibmc_mode_funcs;
      ret = hibmc_de_init(priv);
      if (ret) {
-        drm_err(priv->dev, "failed to init de: %d\n", ret);
+        drm_err(dev, "failed to init de: %d\n", ret);
          return ret;
      }
      ret = hibmc_vdac_init(priv);
      if (ret) {
-        drm_err(priv->dev, "failed to init vdac: %d\n", ret);
+        drm_err(dev, "failed to init vdac: %d\n", ret);
          return ret;
      }

@@ -113,7 +114,7 @@ static int hibmc_kms_init(struct 
hibmc_drm_private *priv)

  static void hibmc_kms_fini(struct hibmc_drm_private *priv)
  {
      if (priv->mode_config_initialized) {
-        drm_mode_config_cleanup(priv->dev);
+        drm_mode_config_cleanup(&priv->dev);
          priv->mode_config_initialized = false;
      }
  }

@@ -202,7 +203,7 @@ static void hibmc_hw_config(struct 
hibmc_drm_private *priv)

  static int hibmc_hw_map(struct hibmc_drm_private *priv)
  {
-    struct drm_device *dev = priv->dev;
+    struct drm_device *dev = &priv->dev;
      struct pci_dev *pdev = dev->pdev;
      resource_size_t addr, size, ioaddr, iosize;
@@ -258,7 +259,7 @@ static int hibmc_unload(struct drm_device *dev)
  static int hibmc_load(struct drm_device *dev)
  {
-    struct hibmc_drm_private *priv;
+    struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
      int ret;
      priv = drmm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -267,7 +268,6 @@ static int hibmc_load(struct drm_device *dev)
          return -ENOMEM;
      }
      dev->dev_private = priv;
-    priv->dev = dev;



I'm sure this either does not build or does not work. There's a call 
to drm_dev_alloc(), which initialized the DRM device. You need to 
assign the returned device here. The embedding of dev only work after 
you switched to devm_drm_dev_alloc() in the next patch.



For the patch at hand, just keep struct hibmc_drm_private.dev as a 
pointer and you should be fine.



Changing drm_device *dev to drm_device dev and using 
devm_drm_dev_alloc does not easily split into two patches.
The patch does not compile well on its own, but it will compile fine 
with patch #2.

Can patch #1 and patch #2 be combined into a single patch,just like V1.


Most of the code in this patch does

   struct drm_device *dev = &priv->dev;

to get dev as a local variable. Why don't you do

   struct drm_device *dev = priv->dev;

?

That's all that's really needed.


+       priv = devm_drm_dev_alloc(&pdev->dev, &hibmc_driver,
+                                 struct hibmc_drm_private, dev);

devm_drm_dev_alloc function requires parameter 4, dev must be a 
non-pointer for it to work. so had to change dev in the 
hibmc_drm_private  to non-pointer.

This is also the reason to change drm_device *dev to drm_device dev.


Best regards
Thomas


Best regards
Thomas


      ret = hibmc_hw_init(priv);
      if (ret)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h 
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h

index f310a83..e35353a 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
@@ -37,7 +37,7 @@ struct hibmc_drm_private {
      resource_size_t  fb_size;
      /* drm */
-    struct drm_device  *dev;
+    struct drm_device dev;
      struct drm_plane primary_plane;
      struct drm_crtc crtc;
      struct drm_encoder encoder;

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c 
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c

index 74e26c2..d35548d 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c

@@ -96,7 +96,7 @@ static const struct drm_encoder_funcs 
hibmc_encoder_funcs = {

  int hibmc_vdac_init(struct hibmc_drm_private *priv)
  {
-    struct drm_device *dev = priv->dev;
+    struct drm_device *dev = &priv->dev;
      struct hibmc_connector *hibmc_connector = &priv->connector;
      struct drm_encoder *encoder = &priv->encoder;
      struct drm_connector *connector = &hibmc_connector->base;

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c 
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c

index 602ece1..e84fb81 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c
@@ -25,7 +25,7 @@ int hibmc_mm_init(struct hibmc_drm_private *hibmc)
  {
      struct drm_vram_mm *vmm;
      int ret;
-    struct drm_device *dev = hibmc->dev;
+    struct drm_device *dev = &hibmc->dev;
      vmm = drm_vram_helper_alloc_mm(dev,
                         pci_resource_start(dev->pdev, 0),
@@ -41,10 +41,12 @@ int hibmc_mm_init(struct hibmc_drm_private *hibmc)
  void hibmc_mm_fini(struct hibmc_drm_private *hibmc)
  {
-    if (!hibmc->dev->vram_mm)
+    struct drm_device *dev = &hibmc->dev;
+
+    if (!dev->vram_mm)
          return;
-    drm_vram_helper_release_mm(hibmc->dev);
+    drm_vram_helper_release_mm(dev);
  }
  int hibmc_dumb_create(struct drm_file *file, struct drm_device *dev,































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