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From: Ayan Halder <ayan.halder@arm.com>
To: Liviu Dudau <liviu.dudau@arm.com>
Cc: airlied@linux.ie, nd@arm.com, seanpaul@chromium.org,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm: Use horizontal and vertical chroma subsampling factor while calculating offsets in the physical address of framebuffer
Date: Mon, 20 Aug 2018 13:38:59 +0100	[thread overview]
Message-ID: <20180820123859.GA2054@arm.com> (raw)
In-Reply-To: <20180820110319.GV907@e110455-lin.cambridge.arm.com>

On Mon, Aug 20, 2018 at 12:03:19PM +0100, Liviu Dudau wrote:
> On Fri, Aug 17, 2018 at 06:33:04PM +0100, Ayan Kumar Halder wrote:
> > For multi-planar formats, while calculating offsets in planes with index greater than 0
> > (ie second plane, third plane, etc), one needs to divide (src_x * cpp) with horizontal
> > chroma subsampling factor and (src_y * pitch) with vertical chroma subsampling factor.
> > 
> > The reason being that the planes contain subsampled (ie reduced) data (by a factor of 2) and thus the
> 
> drop the extraneous "the" at the end of the line.
> 
> > while calculating the byte position coresponding to the x and y co-ordinates, one needs to be
> 
> and drop the extraneous "be" at the end of this line.
> 
> > divide it with the sampling factor.
> > 
> > Signed-off-by: Ayan Kumar halder <ayan.halder@arm.com>
> 
> Otherwise, it looks good to me!
> 
> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
>
Thanks Liviu. I will update the commit message and push this in
drm-misc-next.

> Best regards,
> Liviu
> 
> > ---
> >  drivers/gpu/drm/drm_fb_cma_helper.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
> > index b127061..47e0e2f 100644
> > --- a/drivers/gpu/drm/drm_fb_cma_helper.c
> > +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> > @@ -86,14 +86,21 @@ dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
> >  {
> >  	struct drm_gem_cma_object *obj;
> >  	dma_addr_t paddr;
> > +	u8 h_div = 1, v_div = 1;
> >  
> >  	obj = drm_fb_cma_get_gem_obj(fb, plane);
> >  	if (!obj)
> >  		return 0;
> >  
> >  	paddr = obj->paddr + fb->offsets[plane];
> > -	paddr += fb->format->cpp[plane] * (state->src_x >> 16);
> > -	paddr += fb->pitches[plane] * (state->src_y >> 16);
> > +
> > +	if (plane > 0) {
> > +		h_div = fb->format->hsub;
> > +		v_div = fb->format->vsub;
> > +	}
> > +
> > +	paddr += (fb->format->cpp[plane] * (state->src_x >> 16)) / h_div;
> > +	paddr += (fb->pitches[plane] * (state->src_y >> 16)) / v_div;
> >  
> >  	return paddr;
> >  }
> > -- 
> > 2.7.4
> > 
> 
> -- 
> ====================
> | I would like to |
> | fix the world,  |
> | but they're not |
> | giving me the   |
>  \ source code!  /
>   ---------------
>     ??\_(???)_/??
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

WARNING: multiple messages have this Message-ID (diff)
From: Ayan Halder <ayan.halder@arm.com>
To: Liviu Dudau <liviu.dudau@arm.com>
Cc: airlied@linux.ie, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org, seanpaul@chromium.org,
	nd@arm.com
Subject: Re: [PATCH] drm: Use horizontal and vertical chroma subsampling factor while calculating offsets in the physical address of framebuffer
Date: Mon, 20 Aug 2018 13:38:59 +0100	[thread overview]
Message-ID: <20180820123859.GA2054@arm.com> (raw)
In-Reply-To: <20180820110319.GV907@e110455-lin.cambridge.arm.com>

On Mon, Aug 20, 2018 at 12:03:19PM +0100, Liviu Dudau wrote:
> On Fri, Aug 17, 2018 at 06:33:04PM +0100, Ayan Kumar Halder wrote:
> > For multi-planar formats, while calculating offsets in planes with index greater than 0
> > (ie second plane, third plane, etc), one needs to divide (src_x * cpp) with horizontal
> > chroma subsampling factor and (src_y * pitch) with vertical chroma subsampling factor.
> > 
> > The reason being that the planes contain subsampled (ie reduced) data (by a factor of 2) and thus the
> 
> drop the extraneous "the" at the end of the line.
> 
> > while calculating the byte position coresponding to the x and y co-ordinates, one needs to be
> 
> and drop the extraneous "be" at the end of this line.
> 
> > divide it with the sampling factor.
> > 
> > Signed-off-by: Ayan Kumar halder <ayan.halder@arm.com>
> 
> Otherwise, it looks good to me!
> 
> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
>
Thanks Liviu. I will update the commit message and push this in
drm-misc-next.

> Best regards,
> Liviu
> 
> > ---
> >  drivers/gpu/drm/drm_fb_cma_helper.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
> > index b127061..47e0e2f 100644
> > --- a/drivers/gpu/drm/drm_fb_cma_helper.c
> > +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> > @@ -86,14 +86,21 @@ dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
> >  {
> >  	struct drm_gem_cma_object *obj;
> >  	dma_addr_t paddr;
> > +	u8 h_div = 1, v_div = 1;
> >  
> >  	obj = drm_fb_cma_get_gem_obj(fb, plane);
> >  	if (!obj)
> >  		return 0;
> >  
> >  	paddr = obj->paddr + fb->offsets[plane];
> > -	paddr += fb->format->cpp[plane] * (state->src_x >> 16);
> > -	paddr += fb->pitches[plane] * (state->src_y >> 16);
> > +
> > +	if (plane > 0) {
> > +		h_div = fb->format->hsub;
> > +		v_div = fb->format->vsub;
> > +	}
> > +
> > +	paddr += (fb->format->cpp[plane] * (state->src_x >> 16)) / h_div;
> > +	paddr += (fb->pitches[plane] * (state->src_y >> 16)) / v_div;
> >  
> >  	return paddr;
> >  }
> > -- 
> > 2.7.4
> > 
> 
> -- 
> ====================
> | I would like to |
> | fix the world,  |
> | but they're not |
> | giving me the   |
>  \ source code!  /
>   ---------------
>     ??\_(???)_/??
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2018-08-20 12:39 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-17 17:33 [PATCH] drm: Use horizontal and vertical chroma subsampling factor while calculating offsets in the physical address of framebuffer Ayan Kumar Halder
2018-08-20 11:03 ` Liviu Dudau
2018-08-20 12:38   ` Ayan Halder [this message]
2018-08-20 12:38     ` Ayan Halder
2018-08-20 13:24     ` Liviu Dudau

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