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From: Liviu Dudau <liviu.dudau@arm.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Starkey <brian.starkey@arm.com>,
	Mali DP Maintainers <malidp@foss.arm.com>,
	David Airlie <airlied@linux.ie>,
	Mihail Atanassov <mihail.atanassov@arm.com>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	Shawn Guo <shawn.guo@linaro.org>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm: mali-dp: use div_u64 for expensive 64-bit divisions
Date: Wed, 26 Apr 2017 15:41:08 +0100	[thread overview]
Message-ID: <20170426144108.GD7170@e110455-lin.cambridge.arm.com> (raw)
In-Reply-To: <20170425195712.2017230-1-arnd@arndb.de>

On Tue, Apr 25, 2017 at 09:56:53PM +0200, Arnd Bergmann wrote:
> On 32-bit machines, we can't divide 64-bit integers:
> 
> drivers/gpu/drm/arm/malidp_crtc.o: In function `malidp_crtc_atomic_check':
> malidp_crtc.c:(.text.malidp_crtc_atomic_check+0x3c0): undefined reference to `__aeabi_uldivmod'
> malidp_crtc.c:(.text.malidp_crtc_atomic_check+0x3dc): undefined reference to `__aeabi_uldivmod'
> 
> This calls the div_u64 function explicitly instead.
> 
> Fixes: 4cea4e9f6690 ("drm: mali-dp: Add plane upscaling support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Liviu Dudau <liviu.dudau@arm.com>

I'll push the patch to the mali-dp repository. Dave A., if you have pulled the mali-dp
patches then this will need to go in as well, otherwise I will send an updated pull
request soon.

Best regards,
Liviu

> ---
>  drivers/gpu/drm/arm/malidp_crtc.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
> index 19f1f3b34691..9446a673d469 100644
> --- a/drivers/gpu/drm/arm/malidp_crtc.c
> +++ b/drivers/gpu/drm/arm/malidp_crtc.c
> @@ -266,7 +266,6 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  
>  	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
>  		struct malidp_plane *mp = to_malidp_plane(plane);
> -		u64 crtc_w, crtc_h;
>  		u32 phase;
>  
>  		if (!(mp->layer->id & scaling))
> @@ -276,10 +275,10 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  		 * Convert crtc_[w|h] to U32.32, then divide by U16.16 src_[w|h]
>  		 * to get the U16.16 result.
>  		 */
> -		crtc_w = (u64)pstate->crtc_w << 32;
> -		crtc_h = (u64)pstate->crtc_h << 32;
> -		h_upscale_factor = (u32)(crtc_w / pstate->src_w);
> -		v_upscale_factor = (u32)(crtc_h / pstate->src_h);
> +		h_upscale_factor = div_u64((u64)pstate->crtc_w << 32,
> +					   pstate->src_w);
> +		v_upscale_factor = div_u64((u64)pstate->crtc_h << 32,
> +					   pstate->src_h);
>  
>  		s->enhancer_enable = ((h_upscale_factor >> 16) >= 2 ||
>  				      (v_upscale_factor >> 16) >= 2);
> -- 
> 2.9.0
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

WARNING: multiple messages have this Message-ID (diff)
From: Liviu Dudau <liviu.dudau@arm.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Mali DP Maintainers <malidp@foss.arm.com>,
	Mihail Atanassov <mihail.atanassov@arm.com>
Subject: Re: [PATCH] drm: mali-dp: use div_u64 for expensive 64-bit divisions
Date: Wed, 26 Apr 2017 15:41:08 +0100	[thread overview]
Message-ID: <20170426144108.GD7170@e110455-lin.cambridge.arm.com> (raw)
In-Reply-To: <20170425195712.2017230-1-arnd@arndb.de>

On Tue, Apr 25, 2017 at 09:56:53PM +0200, Arnd Bergmann wrote:
> On 32-bit machines, we can't divide 64-bit integers:
> 
> drivers/gpu/drm/arm/malidp_crtc.o: In function `malidp_crtc_atomic_check':
> malidp_crtc.c:(.text.malidp_crtc_atomic_check+0x3c0): undefined reference to `__aeabi_uldivmod'
> malidp_crtc.c:(.text.malidp_crtc_atomic_check+0x3dc): undefined reference to `__aeabi_uldivmod'
> 
> This calls the div_u64 function explicitly instead.
> 
> Fixes: 4cea4e9f6690 ("drm: mali-dp: Add plane upscaling support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Liviu Dudau <liviu.dudau@arm.com>

I'll push the patch to the mali-dp repository. Dave A., if you have pulled the mali-dp
patches then this will need to go in as well, otherwise I will send an updated pull
request soon.

Best regards,
Liviu

> ---
>  drivers/gpu/drm/arm/malidp_crtc.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
> index 19f1f3b34691..9446a673d469 100644
> --- a/drivers/gpu/drm/arm/malidp_crtc.c
> +++ b/drivers/gpu/drm/arm/malidp_crtc.c
> @@ -266,7 +266,6 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  
>  	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
>  		struct malidp_plane *mp = to_malidp_plane(plane);
> -		u64 crtc_w, crtc_h;
>  		u32 phase;
>  
>  		if (!(mp->layer->id & scaling))
> @@ -276,10 +275,10 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  		 * Convert crtc_[w|h] to U32.32, then divide by U16.16 src_[w|h]
>  		 * to get the U16.16 result.
>  		 */
> -		crtc_w = (u64)pstate->crtc_w << 32;
> -		crtc_h = (u64)pstate->crtc_h << 32;
> -		h_upscale_factor = (u32)(crtc_w / pstate->src_w);
> -		v_upscale_factor = (u32)(crtc_h / pstate->src_h);
> +		h_upscale_factor = div_u64((u64)pstate->crtc_w << 32,
> +					   pstate->src_w);
> +		v_upscale_factor = div_u64((u64)pstate->crtc_h << 32,
> +					   pstate->src_h);
>  
>  		s->enhancer_enable = ((h_upscale_factor >> 16) >= 2 ||
>  				      (v_upscale_factor >> 16) >= 2);
> -- 
> 2.9.0
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯
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  reply	other threads:[~2017-04-26 14:41 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-25 19:56 [PATCH] drm: mali-dp: use div_u64 for expensive 64-bit divisions Arnd Bergmann
2017-04-25 19:56 ` Arnd Bergmann
2017-04-26 14:41 ` Liviu Dudau [this message]
2017-04-26 14:41   ` Liviu Dudau

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