[PATCH 2/3] ARM: OMAP: hwmod: revise deassert sequence
Omar Ramirez Luna
omar.luna at linaro.org
Thu Aug 2 18:20:27 EDT 2012
Hi.
On 2 August 2012 02:52, Paul Walmsley <paul at pwsan.com> wrote:
> On Mon, 16 Jul 2012, Omar Ramirez Luna wrote:
>
>> For a reset sequence to complete cleanly, a module needs its
>> associated clocks to be enabled, otherwise the timeout check
>> in prcm code can print a false failure (failed to hardreset)
>> that occurs because the clocks aren't powered ON and the status
>> bit checked can't transition without them.
>>
>> Signed-off-by: Omar Ramirez Luna <omar.luna at linaro.org>
>
> Is enabling the clocks sufficient?
During my testing it seemed enough, besides it looks clk framework is
doing the same as _omap4_enable_module.
> Or do we also need to enable the
> IP block, e.g. by calling
>
> if (soc_ops.enable_module)
> soc_ops.enable_module(oh);
>
> as we do on OMAP4+ in _enable() ?
Basically this is a call to _omap4_enable_module, and the latter will
"Enable the modulemode inside CLKCTRL".
However, _enable_clocks path which ends calling omap2_dflt_clk_enable
does the same thing with its clk->enable_reg field.
So in _enable:
_enable_clocks(oh);
if (soc_ops.enable_module)
soc_ops.enable_module(oh);
The enable_module part seems redundant to me, since the module should
be already enabled by the first call to _enable_clocks.
Regards,
Omar
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