From mboxrd@z Thu Jan  1 00:00:00 1970
From: mkl@blackshift.org (Marc Kleine-Budde)
Date: Tue, 19 Jun 2012 22:43:04 +0200
Subject: Dove clock support
In-Reply-To: <20120619204210.GA18128@schnuecks.de>
References: <1339978054-8464-1-git-send-email-mkl@blackshift.org>
 <20120618074258.GI4799@lunn.ch> <4FDEDEAE.30502@blackshift.org>
 <20120618080449.GK4799@lunn.ch> <4FDEE6C6.2060101@blackshift.org>
 <20120618084300.GL4799@lunn.ch> <20120618214143.GA20040@schnuecks.de>
 <4FDFA748.10905@googlemail.com> <20120619193251.GR26034@lunn.ch>
 <20120619204210.GA18128@schnuecks.de>
Message-ID: <4FE0E458.40908@blackshift.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 06/19/2012 10:42 PM, Simon Baatz wrote:
> On Tue, Jun 19, 2012 at 09:32:51PM +0200, Andrew Lunn wrote:
>> On Tue, Jun 19, 2012 at 12:10:16AM +0200, Sebastian Hesselbarh wrote:
>>> On 06/18/2012 11:41 PM, Simon Baatz wrote:
>>>> This is not potentially a problem, this is definitively a problem (on kirkwood):
>>>>
>>>> [   12.280783] sata_mv sata_mv.0: cannot get optional clkdev
>>>> [   12.286314] sata_mv sata_mv.0: slots 32 ports 2
>>>> ...
>>>> [   12.665882] ata1: SATA link down (SStatus 0 SControl F300)
>>>> [   13.015881] ata2: SATA link down (SStatus 0 SControl F300)
>>>
>>> Is this because of some bug in kirkwood soc or missing code in
>>> sata_mv.c?
>>>
>>> According to the functional specification of kirkwood there is a
>>> PhyShutdown bit in it's registers. Dove also has this register bit.
>>>
>>> Up to now it looks like the SATA PHY can only be disabled in code,
>>> but there should be an phy_enable, too.
>>
>> Correct.
>>
>> When moving from kirkwoods old clock management to the generic clock
>> framework, i kept the functionality the same. The old code would turn
>> the PHYs off, but have no way to turn them back on again. The new code
>> is the same.
> 
> No, not exactly the same. In the old code, it was sufficient to call
> the respective kirkwood_..._init function to keep the clock and the
> PHY alive. Now, the respective driver needs to enable the clock in
> order to prevent that the clock and the PHY are shut down. 
> 
> If the driver is loaded as a module, the clock and the PHY are
> already shut down at init of the module, which normally would not
> happen previously.
> 
> Should we make this symmetric and add an enable function to gate_fn?
+1

Marc