linux-kernel - Re: [PATCH 1/7] clk: qcom: Mark a few branch clocks with BRANCH_HALT

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Message-ID: <20161102203950.GK16026@codeaurora.org>
Date:   Wed, 2 Nov 2016 13:39:50 -0700
From:   Stephen Boyd <sboyd@...eaurora.org>
To:     Rajendra Nayak <rnayak@...eaurora.org>
Cc:     mturquette@...libre.com, linux-clk@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        tdas@...eaurora.org,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Subject: Re: [PATCH 1/7] clk: qcom: Mark a few branch clocks with
 BRANCH_HALT_DELAY

On 10/19, Rajendra Nayak wrote:
> We seem to have a few branch clocks within gcc for msm8996 which do
> have a valid halt bit but can't be used to check branch enable/disable
> status as they rely on external clocks in some cases and in some 
> others only toggle during an ongoing bus transaction.
> Mark these with BRANCH_HALT_DELAY, so we just add a delay instead.
> 
> Signed-off-by: Rajendra Nayak <rnayak@...eaurora.org>
> ---

Srini tells me that if the pcie pipe clocks are enabled after the
phy is powered up things work fine and the halt bit checks work.
So I don't think we need this patch. Probably the drivers are
enabling all their clocks at probe instead of understanding that
the phy is outputting a clock that goes into gcc to be gated and
then back out into their controller and/or phy.

Also, note that these clocks have parents that should be
populated by the phys, but so far we haven't done that. That
should be fixed as well.

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