Re: kernel panic with latest DSS

From: Koen Kooi <koen@dominion.thruhere.net>
To: Koen Kooi <koen@dominion.thruhere.net>
Cc: Steve Sakoman <sakoman@gmail.com>,
	linux-omap@vger.kernel.org,
	Tomi Valkeinen <Tomi.Valkeinen@nokia.com>
Subject: Re: kernel panic with latest DSS
Date: Thu, 11 Mar 2010 13:45:50 +0100	[thread overview]
Message-ID: <EA594AD7-44AB-4D7A-B576-3D88B948F07C@student.utwente.nl> (raw)
In-Reply-To: <18410E43-78D3-4406-879B-37712FCE8B5C@student.utwente.nl>

Op 11 mrt 2010, om 10:24 heeft Koen Kooi het volgende geschreven:

> 
> Op 10 mrt 2010, om 19:16 heeft Steve Sakoman het volgende geschreven:
> 
>> On Tue, Mar 9, 2010 at 11:58 AM, Steve Sakoman <sakoman@gmail.com> wrote:
>>> I just updated all my Beagle and Overo DSS patches to apply on the
>>> latest linux-omap head.
>>> 
>>> I ran into a slight issue with parsing defaults, but saw that Tomi had
>>> already posted a workaround for that.
>>> 
>>> With that patch applied I get pretty good results until I try to do
>>> something like play a DVD or display video from a webcam.
>>> 
>>> At that point I get a kernel panic.  See below.
>> 
>> I did a little more research on this.
>> 
>> The issue occurs in the following section of code in
>> drivers/video/omap2/dss/dispc.c:
>> 
>> unsigned long dispc_fclk_rate(void)
>> {
>> 	unsigned long r = 0;
>> 
>> 	if (dss_get_dispc_clk_source() == DSS_SRC_DSS1_ALWON_FCLK)
>> 		r = dss_clk_get_rate(DSS_CLK_FCK1);
>> 	else
>> #ifdef CONFIG_OMAP2_DSS_DSI
>> 		r = dsi_get_dsi1_pll_rate();
>> #else
>> 	BUG();
>> #endif
>> 	return r;
>> }
>> 
>> Since my machines don't have DSI displays CONFIG_OMAP2_DSS_DSI is not
>> defined and the BUG() call is triggered.
>> 
>> I don't know enough about what *should* be happening here to propose a
>> fix, but I'll continue looking.
> 
> Not that you need the DSI_PLL config to get tighter timings to do e.g. 74.25MHz for 720p60. I had to rediscover that this week on DM37xx.....

That was supposed to read "note", so you *do* need it.