From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: barebox@lists.infradead.org
Subject: Re: [PATCH] video: imx: assert that image buffer doesn't cross a 4 MiB boundary
Date: Thu, 17 Sep 2015 08:10:52 +0200 [thread overview]
Message-ID: <20150917061052.GM5327@pengutronix.de> (raw)
In-Reply-To: <1442433644-1324-1-git-send-email-u.kleine-koenig@pengutronix.de>
Hello
On Wed, Sep 16, 2015 at 10:00:44PM +0200, Uwe Kleine-König wrote:
> The reference manual (for the i.MX25 in my case) states:
>
> This field must start at a location that enables a complete
> picture to be stored in a 4 Mbyte memory boundary (A [21:0]). A
> [31:22] has a fixed value for a picture’s image.
>
> Check this condition for user-supplied framebuffer values and enforce it
> for driver-allocated buffers.
Maybe add here:
------>8------
If the buffer crosses a 4 MiB boundary the pixels that are "out of
bounds" just appear white on the display.
------>8------
I didn't check if the counter overflows and than picks up data from 4
MiB below the expected memory, but I would be surprised if I had only
0xff there.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
next prev parent reply other threads:[~2015-09-17 6:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-16 20:00 Uwe Kleine-König
2015-09-17 6:10 ` Uwe Kleine-König [this message]
2015-09-21 6:09 ` Sascha Hauer
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=20150917061052.GM5327@pengutronix.de \
--to=u.kleine-koenig@pengutronix.de \
--cc=barebox@lists.infradead.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox