From: Maxime Ripard <maxime@cerno.tech>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Stephen Boyd <sboyd@kernel.org>,
Dmitry Osipenko <digetx@gmail.com>,
Michael Turquette <mturquette@baylibre.com>,
linux-clk@vger.kernel.org, Jonathan Hunter <jonathanh@nvidia.com>,
Peter De Schrijver <pdeschrijver@nvidia.com>,
Prashant Gaikwad <pgaikwad@nvidia.com>,
linux-tegra@vger.kernel.org
Subject: Re: [PATCH v4 65/68] clk: tegra: super: Switch to determine_rate
Date: Thu, 22 Jun 2023 13:24:12 +0200 [thread overview]
Message-ID: <p2qdhxxadsxakzgr2c5n6vs5tbfnjd22faynsl45jzooh7eejf@b5hzujmccljl> (raw)
In-Reply-To: <ZJMYrVl--rCcj1cB@orome>
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Hi,
On Wed, Jun 21, 2023 at 05:35:09PM +0200, Thierry Reding wrote:
> On Tue, Jun 20, 2023 at 12:09:09PM -0700, Stephen Boyd wrote:
> > Quoting Maxime Ripard (2023-06-19 00:26:19)
> > > On Mon, Jun 19, 2023 at 02:38:59AM +0300, Dmitry Osipenko wrote:
> > > > 05.05.2023 14:26, Maxime Ripard пишет:
> > > > >
> > > > > diff --git a/drivers/clk/tegra/clk-super.c b/drivers/clk/tegra/clk-super.c
> > > > > index 3f3a7a203c5f..7ec47942720c 100644
> > > > > --- a/drivers/clk/tegra/clk-super.c
> > > > > +++ b/drivers/clk/tegra/clk-super.c
> > > > > @@ -142,15 +142,22 @@ static const struct clk_ops tegra_clk_super_mux_ops = {
> > > > > .restore_context = clk_super_mux_restore_context,
> > > > > };
> > > > >
> > > > > -static long clk_super_round_rate(struct clk_hw *hw, unsigned long rate,
> > > > > - unsigned long *parent_rate)
> > > > > +static int clk_super_determine_rate(struct clk_hw *hw,
> > > > > + struct clk_rate_request *req)
> > > > > {
> > > > > struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
> > > > > struct clk_hw *div_hw = &super->frac_div.hw;
> > > > > + unsigned long rate;
> > > > >
> > > > > __clk_hw_set_clk(div_hw, hw);
> > > > >
> > > > > - return super->div_ops->round_rate(div_hw, rate, parent_rate);
> > > > > + rate = super->div_ops->round_rate(div_hw, req->rate,
> > > > > + &req->best_parent_rate);
> > > > > + if (rate < 0)
> >
> > There's the report that this condition is never possible. Maybe the
> > previous code was relying on an error value sometimes. Can we add
> > determine_rate to the div_ops and simplify this code? I asked on the
> > list for that earlier.
>
> I was able to reproduce this on a Tegra30 Beaver, but the problem is
> more straightforward than this. The crash I was seeing during boot was
> because cclk_super_determine_rate() was still calling the round_rate()
> callback from tegra_clk_super_ops, which this patch removed (and added
> determine_rate() instead).
>
> The following fixes the problem for me. It's basically converting the
> round_rate() call to an equivalent determine_rate() call.
Thanks for figuring it out :)
> Dmitry, can you verify that this fixes the issue that you were seeing?
>
> Thierry
>
> --- >8 ---
> diff --git a/drivers/clk/tegra/clk-tegra-super-cclk.c b/drivers/clk/tegra/clk-tegra-super-cclk.c
> index 68d7bcd5fc8a..8a2bb4ae4fd2 100644
> --- a/drivers/clk/tegra/clk-tegra-super-cclk.c
> +++ b/drivers/clk/tegra/clk-tegra-super-cclk.c
> @@ -86,9 +86,16 @@ static int cclk_super_determine_rate(struct clk_hw *hw,
> if (rate <= pllp_rate) {
> if (super->flags & TEGRA20_SUPER_CLK)
> rate = pllp_rate;
> - else
> - rate = tegra_clk_super_ops.round_rate(hw, rate,
> - &pllp_rate);
> + else {
> + struct clk_rate_request parent = {
> + .rate = req->rate,
> + .best_parent_rate = pllp_rate,
> + };
If it works and you submit a patch later, this needs to be changed to
clk_hw_init_rate_request()
Maxime
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next prev parent reply other threads:[~2023-06-22 11:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-05 11:25 [PATCH v4 00/68] clk: Make determine_rate mandatory for muxes Maxime Ripard
2023-05-05 11:25 ` [PATCH v4 03/68] clk: Move no reparent case into a separate function Maxime Ripard
[not found] ` <CGME20230613111502eucas1p2644889c9de1abfe1a14a3b549772f247@eucas1p2.samsung.com>
2023-06-13 11:15 ` Marek Szyprowski
[not found] ` <CGME20230613121511eucas1p2595e0de21fadbafc1f6ffdc5636b9271@eucas1p2.samsung.com>
2023-06-13 12:15 ` Marek Szyprowski
2023-06-13 12:29 ` Maxime Ripard
2023-05-05 11:25 ` [PATCH v4 04/68] clk: Introduce clk_hw_determine_rate_no_reparent() Maxime Ripard
2023-05-05 11:25 ` [PATCH v4 34/68] clk: tegra: bpmp: Add a determine_rate hook Maxime Ripard
2023-05-05 11:25 ` [PATCH v4 35/68] clk: tegra: super: " Maxime Ripard
2023-05-05 11:25 ` [PATCH v4 36/68] clk: tegra: periph: " Maxime Ripard
2023-05-05 11:25 ` [PATCH v4 40/68] drm/tegra: sor: " Maxime Ripard
2023-05-05 11:26 ` [PATCH v4 64/68] clk: tegra: periph: Switch to determine_rate Maxime Ripard
2023-05-05 11:26 ` [PATCH v4 65/68] clk: tegra: super: " Maxime Ripard
2023-06-18 23:38 ` Dmitry Osipenko
2023-06-19 7:26 ` Maxime Ripard
2023-06-20 19:09 ` Stephen Boyd
2023-06-21 15:35 ` Thierry Reding
2023-06-22 11:24 ` Maxime Ripard [this message]
2023-06-23 14:51 ` Thierry Reding
2023-06-23 15:02 ` Maxime Ripard
2023-06-22 11:32 ` Dmitry Osipenko
2023-06-30 4:57 ` Stephen Boyd
2023-05-05 11:26 ` [PATCH v4 68/68] clk: Forbid to register a mux without determine_rate Maxime Ripard
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