Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Robert Chiras <robert.chiras@nxp.com>
To: "stefan@agner.ch" <stefan@agner.ch>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>
Cc: "marex@denx.de" <marex@denx.de>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"kernel@pengutronix.de" <kernel@pengutronix.de>,
	"airlied@linux.ie" <airlied@linux.ie>,
	"shawnguo@kernel.org" <shawnguo@kernel.org>,
	"agx@sigxcpu.org" <agx@sigxcpu.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	dl-linux-imx <linux-imx@nxp.com>,
	"daniel@ffwll.ch" <daniel@ffwll.ch>,
	"festevam@gmail.com" <festevam@gmail.com>,
	"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [EXT] Re: [PATCH v2 09/15] dt-bindings: display: Add max-res property for mxsfb
Date: Wed, 14 Aug 2019 11:14:03 +0000
Message-ID: <1565781243.3209.55.camel@nxp.com> (raw)
In-Reply-To: <491aff3d08f24ab4d79a4f8c139d2e44@agner.ch>

Hi Stefan,
On Mi, 2019-08-14 at 13:03 +0200, Stefan Agner wrote:
> On 2019-08-14 12:48, Robert Chiras wrote:
> > 
> > Add new optional property 'max-res', to limit the maximum supported
> > resolution by the MXSFB_DRM driver.
> I would also mention the reason why we need this.
> 
> I guess this needs a vendor prefix as well (fsl,max-res). I also
> would
> like to have the ack of the device tree folks here.
Rob Herring also aked be about this, and I'll copy here the reply, with
explanations:

Indeed, this limitation is actually due to bandwidth limitation, but
the problem is that this limitation comes on i.MX8M (known as mScale
850D), where the memory bandwidth cannot support: GPU/VPU workload in
the same time with both DCSS driving 4k@60 and eLCDIF driving 1080p@60.
Since eLCDIF is a secondary display we though to add the posibility to
limit it's bandwidth by limiting the resolution.
If you say that more details are needed, I can add them in the
description.
> 
> --
> Stefan
> 
> > 
> > 
> > Signed-off-by: Robert Chiras <robert.chiras@nxp.com>
> > ---
> >  Documentation/devicetree/bindings/display/mxsfb.txt | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/display/mxsfb.txt
> > b/Documentation/devicetree/bindings/display/mxsfb.txt
> > index 472e1ea..55e22ed 100644
> > --- a/Documentation/devicetree/bindings/display/mxsfb.txt
> > +++ b/Documentation/devicetree/bindings/display/mxsfb.txt
> > @@ -17,6 +17,12 @@ Required properties:
> >  Required sub-nodes:
> >    - port: The connection to an encoder chip.
> > 
> > +Optional properties:
> > +- max-res:   an array with a maximum of two integers, representing
> > the
> > +             maximum supported resolution, in the form of
> > +             <maxX>, <maxY>; if one of the item is <0>, the
> > default
> > +             driver-defined maximum resolution for that axis is
> > used
> > +
> >  Example:
> > 
> >       lcdif1: display-controller@2220000 {

Thanks,
Robert
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply index

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-14 10:48 [PATCH v2 00/15] Improvements and fixes for mxsfb DRM driver Robert Chiras
2019-08-14 10:48 ` [PATCH v2 01/15] drm/mxsfb: Update mxsfb to support a bridge Robert Chiras
2019-08-14 10:48 ` [PATCH v2 02/15] drm/mxsfb: Read bus flags from bridge if present Robert Chiras
2019-08-14 10:48 ` [PATCH v2 03/15] drm/mxsfb: Add defines for the rest of registers Robert Chiras
2019-08-14 10:48 ` [PATCH v2 04/15] drm/mxsfb: Reset vital register for a proper initialization Robert Chiras
2019-08-14 11:11   ` Stefan Agner
2019-08-14 11:38     ` [EXT] " Robert Chiras
2019-08-14 10:48 ` [PATCH v2 05/15] drm/mxsfb: Update register definitions using bit manipulation defines Robert Chiras
2019-08-14 10:48 ` [PATCH v2 06/15] drm/mxsfb: Update mxsfb with additional pixel formats Robert Chiras
2019-08-14 11:44   ` Daniel Stone
2019-08-14 14:58     ` [EXT] " Robert Chiras
2019-08-14 10:48 ` [PATCH v2 07/15] drm/mxsfb: Fix the vblank events Robert Chiras
2019-08-14 17:31   ` Daniel Vetter
2019-08-14 10:48 ` [PATCH v2 08/15] drm/mxsfb: Signal mode changed when bpp changed Robert Chiras
2019-08-14 10:48 ` [PATCH v2 09/15] dt-bindings: display: Add max-res property for mxsfb Robert Chiras
2019-08-14 11:03   ` Stefan Agner
2019-08-14 11:14     ` Robert Chiras [this message]
2019-08-14 11:25       ` [EXT] " Stefan Agner
2019-08-14 12:03         ` Robert Chiras
2019-08-14 10:48 ` [PATCH v2 10/15] drm/mxsfb: Add max-res property for MXSFB Robert Chiras
2019-08-14 10:48 ` [PATCH v2 11/15] drm/mxsfb: Update mxsfb to support LCD reset Robert Chiras
2019-08-14 10:48 ` [PATCH v2 12/15] drm/mxsfb: Improve the axi clock usage Robert Chiras
2019-08-14 11:06   ` Stefan Agner
2019-08-14 11:35     ` [EXT] " Robert Chiras
2019-08-14 10:48 ` [PATCH v2 13/15] drm/mxsfb: Clear OUTSTANDING_REQS bits Robert Chiras
2019-08-14 10:48 ` [PATCH v2 14/15] drm/mxsfb: Add support for horizontal stride Robert Chiras
2019-08-14 10:48 ` [PATCH v2 15/15] drm/mxsfb: Add support for live pixel format change Robert Chiras

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1565781243.3209.55.camel@nxp.com \
    --to=robert.chiras@nxp.com \
    --cc=agx@sigxcpu.org \
    --cc=airlied@linux.ie \
    --cc=daniel@ffwll.ch \
    --cc=devicetree@vger.kernel.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=festevam@gmail.com \
    --cc=kernel@pengutronix.de \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marex@denx.de \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=s.hauer@pengutronix.de \
    --cc=shawnguo@kernel.org \
    --cc=stefan@agner.ch \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git