[Intel-gfx] [PATCH v7 02/11] drm/i915: Use offsetof() to calculate the offset of members in PVINFO page

[Joonas Lahtinen]

On ti, 2016-06-07 at 11:18 -0400, Zhi Wang wrote:
> To get the offset of the members in PVINFO page, offsetof() looks much
> better than the tricky approach in current code.
> 
> v7:
> 
> - Move "offsetof()" modification into a dedicated patch. (Joonas)
> 
> Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>

It's good idea to add Cc: in patches resulting from discussions (or
Suggested-by:). Then it would be easier to spot for me if I was not
reviewing the series as whole.

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_pvinfo.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h b/drivers/gpu/drm/i915/i915_pvinfo.h
> index 68bdf60..7b3cec4 100644
> --- a/drivers/gpu/drm/i915/i915_pvinfo.h
> +++ b/drivers/gpu/drm/i915/i915_pvinfo.h
> @@ -104,7 +104,7 @@ struct vgt_if {
>  } __packed;
>  
>  #define vgtif_reg(x) \
> -	_MMIO((VGT_PVINFO_PAGE + (long)&((struct vgt_if *)NULL)->x))
> +	_MMIO((VGT_PVINFO_PAGE + offsetof(struct vgt_if, x)))
>  
>  /* vGPU display status to be used by the host side */
>  #define VGT_DRV_DISPLAY_NOT_READY 0
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation