From: Stefan Roese <stefan.roese@gmail.com>
To: Tero Kristo <t-kristo@ti.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>,
linux-omap <linux-omap@vger.kernel.org>,
Paul Walmsley <paul@pwsan.com>,
Mike Turquette <mturquette@linaro.org>
Subject: Re: Odd behavior with dpll4_m4x2_ck on omap3 + DT
Date: Tue, 10 Sep 2013 14:25:19 +0200 [thread overview]
Message-ID: <522F0FAF.3040000@gmail.com> (raw)
In-Reply-To: <522F0CC7.50501@ti.com>
On 10.09.2013 14:12, Tero Kristo wrote:
>> I debugged this a bit and found that this issue (dpll4_m4x2_ck clock is
>> not 2 times dpll4_m4_ck) results from this code:
>>
>> arch/arm/mach-omap2/dpll3xxx.c:
>>
>> unsigned long omap3_clkoutx2_recalc(struct clk_hw *hw,
>> unsigned long parent_rate)
>> {
>> ...
>> if ((v != OMAP3XXX_EN_DPLL_LOCKED) || (dd->flags & DPLL_J_TYPE))
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> rate = parent_rate;
>> else
>> rate = parent_rate * 2;
>> return rate;
>> }
>>
>> As marked above, v is at that early time 0x1 (unmasked value of this
>> register is 0x38310037). So the DPLL4 is not locked but in low power top
>> mode (OMAP3XXX_EN_DPLL_LOCKED = 0x7).
>>
>> Any hint whats missing here?
>
> If it claims it is not locked, it means the DPLL itself is disabled. You
> could try clk_enable for the clock before doing clk_set_rate.
Yes, of course. This solves this issue. Thanks.
Tomi, most likely some clk_enable() / clk_disable() calls are missing
from the PM functions as well?
Cheers,
Stefan
prev parent reply other threads:[~2013-09-10 12:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-28 9:22 Odd behavior with dpll4_m4x2_ck on omap3 + DT Tomi Valkeinen
2013-08-28 9:48 ` Tero Kristo
2013-08-28 10:14 ` Tomi Valkeinen
2013-08-28 11:40 ` Tero Kristo
2013-09-10 11:33 ` Stefan Roese
2013-09-10 12:12 ` Tero Kristo
2013-09-10 12:19 ` Tomi Valkeinen
2013-09-10 12:24 ` Tero Kristo
2013-09-10 12:40 ` Tomi Valkeinen
2013-09-10 13:17 ` Tero Kristo
2013-09-10 21:17 ` Mike Turquette
2013-09-10 21:57 ` Mike Turquette
2013-09-11 7:21 ` Tomi Valkeinen
2013-09-13 7:51 ` Stefan Roese
2013-09-13 11:34 ` Tero Kristo
2013-09-16 19:45 ` Mike Turquette
2013-09-27 8:41 ` Tomi Valkeinen
2013-09-27 11:24 ` Tero Kristo
2013-09-30 7:56 ` Tomi Valkeinen
2013-10-07 8:21 ` Paul Walmsley
2013-10-08 1:35 ` Mike Turquette
2013-10-13 20:17 ` Paul Walmsley
2013-09-10 12:25 ` Stefan Roese [this message]
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