linux-kernel - Re: [PATCH] drm: Consider drivers setting DRIVER_ATOMIC as atomic.

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Message-ID: <20180622082954.GF2958@phenom.ffwll.local>
Date:   Fri, 22 Jun 2018 10:29:54 +0200
From:   Daniel Vetter <daniel@...ll.ch>
To:     Eric Anholt <eric@...olt.net>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm: Consider drivers setting DRIVER_ATOMIC as atomic.

On Thu, Jun 21, 2018 at 12:54:28PM -0700, Eric Anholt wrote:
> Drivers such as vc4 don't initialize mode_config.funcs until later in
> initialization, but we know they're atomic since they've got the flag
> set.  This avoids oopsing on dereferencing funcs in the new atomic
> methods sanity checks.
> 
> I moved the atomic check function down below the core flag check, to
> avoid needing a prototype.
> 
> Signed-off-by: Eric Anholt <eric@...olt.net>
> Fixes: ba1f665f161c ("drm: Add checks for atomic_[duplicate/destroy]_state with atomic drivers")

Reviewed-by: Daniel Vetter <daniel.vetter@...ll.ch>

btw, dim fixes also generates Cc: tags for you (author/reviewer/maintainer
of the commit your fixing), besides just the Fixes: line.
-Daniel

> ---
>  include/drm/drmP.h | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index f5099c12c6a6..c5dfbdb7271d 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -97,6 +97,16 @@ struct pci_controller;
>  
>  #define DRM_IF_VERSION(maj, min) (maj << 16 | min)
>  
> +#define DRM_SWITCH_POWER_ON 0
> +#define DRM_SWITCH_POWER_OFF 1
> +#define DRM_SWITCH_POWER_CHANGING 2
> +#define DRM_SWITCH_POWER_DYNAMIC_OFF 3
> +
> +static inline bool drm_core_check_feature(struct drm_device *dev, int feature)
> +{
> +	return dev->driver->driver_features & feature;
> +}
> +
>  /**
>   * drm_drv_uses_atomic_modeset - check if the driver implements
>   * atomic_commit()
> @@ -107,17 +117,8 @@ struct pci_controller;
>   */
>  static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
>  {
> -	return dev->mode_config.funcs->atomic_commit != NULL;
> -}
> -
> -#define DRM_SWITCH_POWER_ON 0
> -#define DRM_SWITCH_POWER_OFF 1
> -#define DRM_SWITCH_POWER_CHANGING 2
> -#define DRM_SWITCH_POWER_DYNAMIC_OFF 3
> -
> -static inline bool drm_core_check_feature(struct drm_device *dev, int feature)
> -{
> -	return dev->driver->driver_features & feature;
> +	return drm_core_check_feature(dev, DRIVER_ATOMIC) ||
> +		dev->mode_config.funcs->atomic_commit != NULL;
>  }
>  
>  /* returns true if currently okay to sleep */
> -- 
> 2.18.0.rc2
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

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

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