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

[Thomas Zimmermann]

Hi

Am 01.12.20 um 14:05 schrieb tiantao (H):
> 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 <tiantao6@xxxxxxxxxxxxx>
> > > > > ---
> > > > >   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.

Yes, but that's what patch 2 is about. Patch 1 is about simplifying 
these pointer dereferences into local variables. For this, all you need is

	struct drm_device *dev = priv->dev;

In patch 2, these lines are then changed to

	struct drm_device *dev = &priv->dev;

That makes 2 self-contained patches.

Best regards
Thomas

> > 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,

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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