From: u.kleine-koenig@pengutronix.de (Uwe Kleine-König)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: mxs: Change duart device to use amba-pl011
Date: Wed, 29 Dec 2010 09:38:35 +0100 [thread overview]
Message-ID: <20101229083835.GO14221@pengutronix.de> (raw)
In-Reply-To: <20101227114938.GA13154@freescale.com>
Hello Shawn,
On Mon, Dec 27, 2010 at 07:49:40PM +0800, Shawn Guo wrote:
> On Wed, Dec 22, 2010 at 09:25:42PM +0100, Uwe Kleine-K?nig wrote:
> > On Tue, Dec 21, 2010 at 09:12:10PM +0800, Shawn Guo wrote:
> > > The mxs duart is actually an amba-pl011 device. This commit changes
> > > the duart device code to dynamically allocate amba-pl011 device,
> > > so that drivers/serial/amba-pl011.c can be used on mxs.
> > I have problems using this. The problem I found up to now is that
> > during probe of the device (triggered by mxs_add_duart ->
> > amba_device_register -> amba_put_disable_pclk) the uart clock is
> > disabled. This happens because initially its usage count is 0 but the
> > clock is enabled by barebox. clk_enable doesn't hurt, but in the
> > matching clk_disable the usage count drops to zero again and so the
> > clock is disabled in hardware. After that no further outputs can be
> > seen.
> >
> I did not see this problem. It's true that the clock is turned off
> in amba_device_register. But later, the clock will be turned on
> again by amba_probe -> amba_get_enable_pclk very soon.
This is only a problem with DEBUG_LL I guess.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | http://www.pengutronix.de/ |
next prev parent reply other threads:[~2010-12-29 8:38 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-20 14:57 [PATCH v8 00/15] ARM: mxs: Add initial support for MX23 and MX28 Shawn Guo
2010-12-20 14:57 ` [PATCH v8 05/15] ARM: mxs: Add low-level debug UART support Shawn Guo
2010-12-20 14:57 ` [PATCH v8 08/15] ARM: mxs: Add iomux support Shawn Guo
2010-12-20 14:57 ` [PATCH v8 13/15] ARM: mxs: Add initial mx23evk support Shawn Guo
2010-12-20 21:29 ` [PATCH v8 00/15] ARM: mxs: Add initial support for MX23 and MX28 Uwe Kleine-König
2010-12-21 8:45 ` Shawn Guo
2010-12-21 13:26 ` Shawn Guo
2010-12-21 13:12 ` [PATCH] ARM: mxs: Change duart device to use amba-pl011 Shawn Guo
2010-12-21 20:31 ` Wolfram Sang
2010-12-22 2:10 ` Shawn Guo
2010-12-22 11:41 ` Wolfram Sang
2010-12-22 20:25 ` Uwe Kleine-König
2010-12-27 11:49 ` Shawn Guo
2010-12-29 8:38 ` Uwe Kleine-König [this message]
2011-01-03 10:39 ` Russell King - ARM Linux
2011-01-04 5:41 ` Shawn Guo
2011-01-03 10:35 ` Russell King - ARM Linux
2010-12-28 15:23 ` [PATCH v2] " Shawn Guo
2010-12-29 9:12 ` Uwe Kleine-König
2010-12-31 5:16 ` Shawn Guo
2010-12-31 5:50 ` [PATCH v3] " Shawn Guo
2011-01-04 6:20 ` [PATCH v4] " Shawn Guo
2011-01-10 13:34 ` Wolfram Sang
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