Re: [PATCH 3/7] Add i.MX5 framebuffer driver

From: Jason Chen <weitway@gmail.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org,
	Paul Mundt <lethal@linux-sh.org>,
	Samuel Ortiz <sameo@linux.intel.com>
Subject: Re: [PATCH 3/7] Add i.MX5 framebuffer driver
Date: Sat, 19 Feb 2011 10:22:08 +0800	[thread overview]
Message-ID: <AANLkTi=hm41HUtwXJSdfGtjj2pRo1xAv1AmZ5zaTp5Sj@mail.gmail.com> (raw)
In-Reply-To: <20110218095221.GK24426@pengutronix.de>

hi, Sascha,

2011/2/18 Sascha Hauer <s.hauer@pengutronix.de>:
> Hi Jason,
>
> On Fri, Feb 18, 2011 at 05:22:09PM +0800, Jason Chen wrote:
>> hi, Sasha,
>>
>> > +       if (var->vmode & FB_VMODE_ODD_FLD_FIRST) /* PAL */
>> > +               sig_cfg.odd_field_first = 1;
>> > +       if (var->sync & FB_SYNC_EXT)
>> > +               sig_cfg.ext_clk = 1;
>> > +       if (var->sync & FB_SYNC_HOR_HIGH_ACT)
>> > +               sig_cfg.Hsync_pol = 1;
>> Please remove FB_SYNC_EXT support.
>
> No problem, can do. But why? Is it nonfunctional in the hardware
> or is it that the current code just misses more pieces to support
> this?
>
This flag represents external sync, some application will not check
this flag when they reset fb var, for example, X server fb driver will
ignore it, if so, the ipu external clock can not be set correctly.
I think ipu should decide external clock usage by other method. The
latest method in freesacle mainline is decide it automatically -- if
internal clock can not fit target clock rate well, switch it to
external.
>>
>> +static void imx_ipu_fb_disable_overlay(struct fb_info *ovl)
>> +{
>> +       struct imx_ipu_fb_info *mxc_ovl = ovl->par;
>> +
>> +       if (!mxc_ovl->enabled)
>> +               return;
>> +
>> +       ipu_dp_disable_fg(mxc_ovl->dp);
>> +       ipu_wait_for_interrupt(451, 100);
>> +       ipu_idmac_disable_channel(mxc_ovl->ipu_ch);
>> +       ipu_dmfc_disable_channel(mxc_ovl->dmfc);
>> +       mxc_ovl->enabled = 0;
>> +}
>> Had better has a definition of ipu irq 451.
>
> Ok.
>
> Sascha
>
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