linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jyri Sarha <jsarha@ti.com>
To: Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	David Airlie <airlied@linux.ie>,
	Kevin Hilman <khilman@baylibre.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Sekhar Nori <nsekhar@ti.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	linux-drm <dri-devel@lists.freedesktop.org>,
	Peter Ujfalusi <peter.ujfalusi@ti.com>,
	arm-soc <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] drm: tilcdc: reduce max_width for revision 1
Date: Mon, 21 Nov 2016 19:26:07 +0200	[thread overview]
Message-ID: <2013ba47-e7e4-045e-0232-4ebd7450c3ad@ti.com> (raw)
In-Reply-To: <1479748590-3962-2-git-send-email-bgolaszewski@baylibre.com>

On 11/21/16 19:16, Bartosz Golaszewski wrote:
> It has been determined that the highest resolution supported correctly
> by LCDC rev1 is 800x600. Reduce the max_width value for rev1 to 800 in
> crtc_max_width().
> 

I don't think this is the right way to limit the supported video modes.
There is technically there is no such limit, is there?

If memory bandwidth is limiting the functionality of higher resolutions,
you should use "max-bandwidth" tilcdc device-tree property [1].

Cheers,
Jyri

[1] In "Documentation/devicetree/bindings/display/tilcdc/tilcdc.txt":
Optional properties:
 - max-bandwidth: The maximum pixels per second that the memory
   interface / lcd controller combination can sustain



> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> index dfe3dd0..9081de5 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> @@ -683,7 +683,7 @@ int tilcdc_crtc_max_width(struct drm_crtc *crtc)
>  	int max_width = 0;
>  
>  	if (priv->rev == 1)
> -		max_width = 1024;
> +		max_width = 800;
>  	else if (priv->rev == 2)
>  		max_width = 2048;
>  
> 

  reply	other threads:[~2016-11-21 17:26 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-21 17:16 [PATCH] drm: tilcdc: reduce max_width for revision 1 Bartosz Golaszewski
2016-11-21 17:16 ` Bartosz Golaszewski
2016-11-21 17:26   ` Jyri Sarha [this message]
2016-11-21 17:29     ` Bartosz Golaszewski

Reply instructions:

You may reply publicly 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=2013ba47-e7e4-045e-0232-4ebd7450c3ad@ti.com \
    --to=jsarha@ti.com \
    --cc=airlied@linux.ie \
    --cc=bgolaszewski@baylibre.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=khilman@baylibre.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mturquette@baylibre.com \
    --cc=nsekhar@ti.com \
    --cc=peter.ujfalusi@ti.com \
    --cc=tomi.valkeinen@ti.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).