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From: Paul Walmsley <paul@pwsan.com>
To: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "Cousson, Benoit" <b-cousson@ti.com>,
	"Hilman, Kevin" <khilman@ti.com>,
	"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCHv2 2/2] OMAP: add omap_device_reset()
Date: Sun, 29 May 2011 20:24:54 -0600 (MDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1105292022080.8973@utopia.booyaka.com> (raw)
In-Reply-To: <1306500367.1905.18.camel@deskari>

Hi Tomi,

On Fri, 27 May 2011, Tomi Valkeinen wrote:

> DSS driver has been designed so that it resets the HW before it begins
> programming it. That way we get the HW into known state. Otherwise we
> need to be extra careful to program all possible registers to a sane
> value. Not impossible, of course, but requires extra work.
> 
> I noticed the problem with DSI driver, it didn't work anymore if I
> didn't reset it.

One thing that I don't quite understand about this thread is that the 
hwmod code should be resetting the DSS hwmods when the system boots.  Is 
something not working with this process?

That is a separate case from the error recovery case.  Sounds like we may 
need to expose a reset function for that purpose as well.  Tomi, I don't 
think your proposed patch is enough for this, though: we'd also need to 
reset the hwmod internal state for that module, and reprogram the 
SYSCONFIG bits, etc. as mach-omap2/omap_hwmod.c:_setup() does.


- Paul

WARNING: multiple messages have this Message-ID (diff)
From: paul@pwsan.com (Paul Walmsley)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 2/2] OMAP: add omap_device_reset()
Date: Sun, 29 May 2011 20:24:54 -0600 (MDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1105292022080.8973@utopia.booyaka.com> (raw)
In-Reply-To: <1306500367.1905.18.camel@deskari>

Hi Tomi,

On Fri, 27 May 2011, Tomi Valkeinen wrote:

> DSS driver has been designed so that it resets the HW before it begins
> programming it. That way we get the HW into known state. Otherwise we
> need to be extra careful to program all possible registers to a sane
> value. Not impossible, of course, but requires extra work.
> 
> I noticed the problem with DSI driver, it didn't work anymore if I
> didn't reset it.

One thing that I don't quite understand about this thread is that the 
hwmod code should be resetting the DSS hwmods when the system boots.  Is 
something not working with this process?

That is a separate case from the error recovery case.  Sounds like we may 
need to expose a reset function for that purpose as well.  Tomi, I don't 
think your proposed patch is enough for this, though: we'd also need to 
reset the hwmod internal state for that module, and reprogram the 
SYSCONFIG bits, etc. as mach-omap2/omap_hwmod.c:_setup() does.


- Paul

  parent reply	other threads:[~2011-05-30  2:24 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-27  7:38 [PATCHv2 0/2] Some omap_device/hwmod/pwrdomain patches Tomi Valkeinen
2011-05-27  7:38 ` Tomi Valkeinen
2011-05-27  7:38 ` [PATCHv2 1/2] OMAP: change get_context_loss_count ret value to int Tomi Valkeinen
2011-05-27  7:38   ` Tomi Valkeinen
2011-05-27  7:38 ` [PATCHv2 2/2] OMAP: add omap_device_reset() Tomi Valkeinen
2011-05-27  7:38   ` Tomi Valkeinen
2011-05-27 12:38   ` Cousson, Benoit
2011-05-27 12:38     ` Cousson, Benoit
2011-05-27 12:46     ` Tomi Valkeinen
2011-05-27 12:46       ` Tomi Valkeinen
2011-05-27 14:43       ` Cousson, Benoit
2011-05-27 14:43         ` Cousson, Benoit
2011-05-27 14:51         ` Santosh Shilimkar
2011-05-27 14:51           ` Santosh Shilimkar
2011-05-27 15:00           ` Cousson, Benoit
2011-05-27 15:00             ` Cousson, Benoit
2011-05-27 15:06             ` Santosh Shilimkar
2011-05-27 15:06               ` Santosh Shilimkar
2011-05-27 16:40         ` Tomi Valkeinen
2011-05-27 16:40           ` Tomi Valkeinen
2011-05-30  2:15           ` Paul Walmsley
2011-05-30  2:15             ` Paul Walmsley
2011-05-30  6:00             ` Tomi Valkeinen
2011-05-30  6:00               ` Tomi Valkeinen
2011-05-30  8:49             ` Cousson, Benoit
2011-05-30  8:49               ` Cousson, Benoit
2011-05-30  2:24       ` Paul Walmsley [this message]
2011-05-30  2:24         ` Paul Walmsley
2011-05-30  5:55         ` Tomi Valkeinen
2011-05-30  5:55           ` Tomi Valkeinen

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