linux-fbdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Robin van der Gracht <robin@protonic.nl>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [BUGFIX] video/mxsfb: fix crash when unblanking the display
Date: Wed, 18 Jul 2012 09:29:58 +0000	[thread overview]
Message-ID: <50068216.9020605@protonic.nl> (raw)
In-Reply-To: <20209.35406.958883.977664@ipc1.ka-ro>

Hi Lothar,
> Hi,
>
> Lothar Waßmann writes:
>> The VDCTRL4 register does not provide the MXS SET/CLR/TOGGLE feature.
>> The write in mxsfb_disable_controller() sets the data_cnt for the LCD
>> DMA to 0 which obviously means the max. count for the LCD DMA and
>> leads to overwriting arbitrary memory when the display is unblanked.
>>
>> Signed-off-by: Lothar Waßmann<LW@KARO-electronics.de>
>> ---
>>   drivers/video/mxsfb.c |    3 ++-
>>   1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
>> index d837d63..03cb95a 100644
>> --- a/drivers/video/mxsfb.c
>> +++ b/drivers/video/mxsfb.c
>> @@ -366,7 +366,8 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
>>   		loop--;
>>   	}
>>
>> -	writel(VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4 + REG_CLR);
>> +	reg = readl(host->base + LCDC_VDCTRL4);
>> +	writel(reg&  ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4);
>>
>>   	clk_disable(host->clk);
>>
>> -- 
>> 1.5.6.5
>>
> Ping. Any comments on this?
>
>
> Lothar Waßmann
I've encountered this problem to, and i can confirm your patch fixed it.
The VDCTRL4 register has no CLR feature.

Regards,

-- 
Robin van der Gracht
Protonic Holland.
tel.: +31 (0) 229 212928
fax.: +31 (0) 229 210930
Factorij 36 / 1689 AL Zwaag


      reply	other threads:[~2012-07-18  9:29 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-06 12:27 [BUGFIX] video/mxsfb: fix crash when unblanking the display Lothar Waßmann
2011-12-21  7:27 ` Lothar Waßmann
2012-07-18  9:29   ` Robin van der Gracht [this message]

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=50068216.9020605@protonic.nl \
    --to=robin@protonic.nl \
    --cc=linux-arm-kernel@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;
as well as URLs for NNTP newsgroup(s).