Re: [PATCH v11 1/4] rockchip/rga: v4l2 m2m support

From: "Heiko Stübner" <heiko@sntech.de>
To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Jacob Chen <jacob-chen@iotwrt.com>,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	robh+dt@kernel.org, mchehab@kernel.org,
	linux-media@vger.kernel.org,
	laurent.pinchart+renesas@ideasonboard.com,
	hans.verkuil@cisco.com
Subject: Re: [PATCH v11 1/4] rockchip/rga: v4l2 m2m support
Date: Mon, 09 Oct 2017 14:52:06 +0200	[thread overview]
Message-ID: <1723232.PDSGHSTtIa@diego> (raw)
In-Reply-To: <39318451-a078-3451-47f8-9205a31cadb5@xs4all.nl>

Hi Hans,

Am Montag, 9. Oktober 2017, 14:48:13 CEST schrieb Hans Verkuil:
> On 09/10/17 11:04, Jacob Chen wrote:
> > Rockchip RGA is a separate 2D raster graphic acceleration unit. It
> > accelerates 2D graphics operations, such as point/line drawing, image
> > scaling, rotation, BitBLT, alpha blending and image blur/sharpness
> > 
> > The driver supports various operations from the rendering pipeline.
> > 
> >  - copy
> >  - fast solid color fill
> >  - rotation
> >  - flip
> >  - alpha blending
> > 
> > The code in rga-hw.c is used to configure regs according to operations
> > The code in rga-buf.c is used to create private mmu table for RGA.
> > 
> > Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
> 
> I ran checkpatch --strict on this patch and I found a few small issues:
> 
> WARNING: Avoid crashing the kernel - try using WARN_ON & recovery code
> rather than BUG() or BUG_ON() #1222: FILE:
> drivers/media/platform/rockchip/rga/rga.c:89:
> +               BUG_ON(!ctx);
> 
> WARNING: Avoid crashing the kernel - try using WARN_ON & recovery code
> rather than BUG() or BUG_ON() #1229: FILE:
> drivers/media/platform/rockchip/rga/rga.c:96:
> +               BUG_ON(!src);
> 
> WARNING: Avoid crashing the kernel - try using WARN_ON & recovery code
> rather than BUG() or BUG_ON() #1230: FILE:
> drivers/media/platform/rockchip/rga/rga.c:97:
> +               BUG_ON(!dst);
> 
> I think you can use WARN_ON here and just return.
> 
> CHECK: struct mutex definition without comment
> #2235: FILE: drivers/media/platform/rockchip/rga/rga.h:84:
> +       struct mutex mutex;
> 
> CHECK: spinlock_t definition without comment
> #2236: FILE: drivers/media/platform/rockchip/rga/rga.h:85:
> +       spinlock_t ctrl_lock;
> 
> These two fields need a comment describing what the locks protect.
> 
> Also move patch 4/4 to the beginning of the patch series. The bindings
> patch should come before the driver.
> 
> If I have a v12 with these issues fixed and a MAINTAINERS patch, then
> I'll take it on Friday.
> 
> Do you want me to take the dts patches or will they go through another tree?

I'd prefer for me to pick up the dts patches ("ARM: dts" and "arm64: dts:"), 
as otherwise we always get conflicts and confusion :-)

I'm monitoring this series, so after you pick the binding + driver, I can
just pick the other two.

Thanks
Heiko