Re: [PATCH v4] drm/bochs: add drm_driver.release callback.

2020-02-12 Thread Gerd Hoffmann
On Tue, Feb 11, 2020 at 03:19:56PM +0100, Daniel Vetter wrote:
> On Tue, Feb 11, 2020 at 02:52:18PM +0100, Gerd Hoffmann wrote:
> > Call bochs_unload via drm_driver.release to make sure we release stuff
> > when it is safe to do so.  Use drm_dev_{enter,exit,unplug} to avoid
> > touching hardware after device removal.  Tidy up here and there.
> > 
> > v4: add changelog.
> > v3: use drm_dev_*().
> > v2: move hardware deinit to pci_remove().
> > 
> > Signed-off-by: Gerd Hoffmann 
> 
> Reviewed-by: Daniel Vetter 
> 
> Btw I checked around whether there's anything else that obviously needs a
> drm_dev_enter/exit, and I spotted the !bochs->mmio check in
> bochs_hw_load_edid. That one looks like cargo-cult, there's a single
> caller in the init path, so either mmio works at that point or this is
> dead code ... slightly confusing.

FYI:  bochs->mmio actually can be NULL when running on very old qemu
versions, the mmio bar was added in qemu release 1.3.  All the register
access functions in bochs_hw.c have a fallback going to ioports because
of that.  So there is a reason for the check, even though it is highly
unlikely that mmio actually is NULL these days.  qemu 1.3 was released
in 2013 ...

cheers,
  Gerd

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Re: [PATCH v4] drm/bochs: add drm_driver.release callback.

2020-02-11 Thread Daniel Vetter
On Tue, Feb 11, 2020 at 02:52:18PM +0100, Gerd Hoffmann wrote:
> Call bochs_unload via drm_driver.release to make sure we release stuff
> when it is safe to do so.  Use drm_dev_{enter,exit,unplug} to avoid
> touching hardware after device removal.  Tidy up here and there.
> 
> v4: add changelog.
> v3: use drm_dev_*().
> v2: move hardware deinit to pci_remove().
> 
> Signed-off-by: Gerd Hoffmann 

Reviewed-by: Daniel Vetter 

Btw I checked around whether there's anything else that obviously needs a
drm_dev_enter/exit, and I spotted the !bochs->mmio check in
bochs_hw_load_edid. That one looks like cargo-cult, there's a single
caller in the init path, so either mmio works at that point or this is
dead code ... slightly confusing.
-Daniel

> ---
>  drivers/gpu/drm/bochs/bochs_drv.c |  6 +++---
>  drivers/gpu/drm/bochs/bochs_hw.c  | 24 +++-
>  2 files changed, 26 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bochs/bochs_drv.c 
> b/drivers/gpu/drm/bochs/bochs_drv.c
> index 10460878414e..addb0568c1af 100644
> --- a/drivers/gpu/drm/bochs/bochs_drv.c
> +++ b/drivers/gpu/drm/bochs/bochs_drv.c
> @@ -23,7 +23,6 @@ static void bochs_unload(struct drm_device *dev)
>  
>   bochs_kms_fini(bochs);
>   bochs_mm_fini(bochs);
> - bochs_hw_fini(dev);
>   kfree(bochs);
>   dev->dev_private = NULL;
>  }
> @@ -69,6 +68,7 @@ static struct drm_driver bochs_driver = {
>   .major  = 1,
>   .minor  = 0,
>   DRM_GEM_VRAM_DRIVER,
> + .release= bochs_unload,
>  };
>  
>  /* -- */
> @@ -148,9 +148,9 @@ static void bochs_pci_remove(struct pci_dev *pdev)
>  {
>   struct drm_device *dev = pci_get_drvdata(pdev);
>  
> + drm_dev_unplug(dev);
>   drm_atomic_helper_shutdown(dev);
> - drm_dev_unregister(dev);
> - bochs_unload(dev);
> + bochs_hw_fini(dev);
>   drm_dev_put(dev);
>  }
>  
> diff --git a/drivers/gpu/drm/bochs/bochs_hw.c 
> b/drivers/gpu/drm/bochs/bochs_hw.c
> index b615b7dfdd9d..952199cc0462 100644
> --- a/drivers/gpu/drm/bochs/bochs_hw.c
> +++ b/drivers/gpu/drm/bochs/bochs_hw.c
> @@ -4,6 +4,7 @@
>  
>  #include 
>  
> +#include 
>  #include 
>  
>  #include "bochs.h"
> @@ -194,6 +195,8 @@ void bochs_hw_fini(struct drm_device *dev)
>  {
>   struct bochs_device *bochs = dev->dev_private;
>  
> + /* TODO: shot down existing vram mappings */
> +
>   if (bochs->mmio)
>   iounmap(bochs->mmio);
>   if (bochs->ioports)
> @@ -207,6 +210,11 @@ void bochs_hw_fini(struct drm_device *dev)
>  void bochs_hw_setmode(struct bochs_device *bochs,
> struct drm_display_mode *mode)
>  {
> + int idx;
> +
> + if (!drm_dev_enter(bochs->dev, ))
> + return;
> +
>   bochs->xres = mode->hdisplay;
>   bochs->yres = mode->vdisplay;
>   bochs->bpp = 32;
> @@ -232,11 +240,18 @@ void bochs_hw_setmode(struct bochs_device *bochs,
>  
>   bochs_dispi_write(bochs, VBE_DISPI_INDEX_ENABLE,
> VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED);
> +
> + drm_dev_exit(idx);
>  }
>  
>  void bochs_hw_setformat(struct bochs_device *bochs,
>   const struct drm_format_info *format)
>  {
> + int idx;
> +
> + if (!drm_dev_enter(bochs->dev, ))
> + return;
> +
>   DRM_DEBUG_DRIVER("format %c%c%c%c\n",
>(format->format >>  0) & 0xff,
>(format->format >>  8) & 0xff,
> @@ -256,13 +271,18 @@ void bochs_hw_setformat(struct bochs_device *bochs,
> __func__, format->format);
>   break;
>   }
> +
> + drm_dev_exit(idx);
>  }
>  
>  void bochs_hw_setbase(struct bochs_device *bochs,
> int x, int y, int stride, u64 addr)
>  {
>   unsigned long offset;
> - unsigned int vx, vy, vwidth;
> + unsigned int vx, vy, vwidth, idx;
> +
> + if (!drm_dev_enter(bochs->dev, ))
> + return;
>  
>   bochs->stride = stride;
>   offset = (unsigned long)addr +
> @@ -277,4 +297,6 @@ void bochs_hw_setbase(struct bochs_device *bochs,
>   bochs_dispi_write(bochs, VBE_DISPI_INDEX_VIRT_WIDTH, vwidth);
>   bochs_dispi_write(bochs, VBE_DISPI_INDEX_X_OFFSET, vx);
>   bochs_dispi_write(bochs, VBE_DISPI_INDEX_Y_OFFSET, vy);
> +
> + drm_dev_exit(idx);
>  }
> -- 
> 2.18.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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