All of lore.kernel.org
 help / color / mirror / Atom feed
From: Michael Jones <michael.jones@matrix-vision.de>
To: linux-media ML <linux-media@vger.kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Subject: capture_mem limitations in OMAP ISP
Date: Tue, 03 Jul 2012 11:46:33 +0200	[thread overview]
Message-ID: <4FF2BF79.2020302@matrix-vision.de> (raw)

Hi Laurent & co.,

I'm looking at the memory limitations in the omap3isp driver.  'struct 
isp_video' contains member 'capture_mem', which is set separately for 
each of our v4l2 video device nodes.  The CCDC, for example, has 
capture_mem = 4096 * 4096 * 3 = 48MB, while the previewer and resizer 
each have twice that. Where do these numbers come from?

Is the CCDC incapable of DMA'ing more than 48MB into memory?  I know 
that ISP_VIDEO_MAX_BUFFERS also limits the # of buffers, but I assume 
this is basically an arbitrary number so we can have a finite array of 
isp_video_buffer's.  The 48MB, on the other hand, looks like it might 
have a good reason.

thanks,
Michael

MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler
Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner, Erhard Meier

             reply	other threads:[~2012-07-03  9:44 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-03  9:46 Michael Jones [this message]
2012-07-05 16:36 ` capture_mem limitations in OMAP ISP Laurent Pinchart

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=4FF2BF79.2020302@matrix-vision.de \
    --to=michael.jones@matrix-vision.de \
    --cc=laurent.pinchart@ideasonboard.com \
    --cc=linux-media@vger.kernel.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.