linux-kernel - Re: [PATCH v1 5/5] clk: tegra: divider: Mark Memory Controller clock as read-only

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Date:   Fri, 12 Apr 2019 16:54:01 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Peter De Schrijver <pdeschrijver@...dia.com>,
        Prashant Gaikwad <pgaikwad@...dia.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Joseph Lo <josephl@...dia.com>
Cc:     linux-clk@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 5/5] clk: tegra: divider: Mark Memory Controller clock
 as read-only

12.04.2019 1:02, Dmitry Osipenko пишет:
> The Memory Controller clock rate can't be simply changed and nothing in
> kernel need to change the rate, hence let's make the clock read-only.
> 
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
>  drivers/clk/tegra/clk-divider.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c
> index 205fe8ff63f0..f891bbb0d06d 100644
> --- a/drivers/clk/tegra/clk-divider.c
> +++ b/drivers/clk/tegra/clk-divider.c
> @@ -175,6 +175,7 @@ struct clk *tegra_clk_register_mc(const char *name, const char *parent_name,
>  				  void __iomem *reg, spinlock_t *lock)
>  {
>  	return clk_register_divider_table(NULL, name, parent_name,
> -					  CLK_IS_CRITICAL, reg, 16, 1, 0,
> -					  mc_div_table, lock);
> +					  CLK_IS_CRITICAL |
> +					  CLK_DIVIDER_READ_ONLY,
> +					  reg, 16, 1, 0, mc_div_table, lock);
>  }
> 

Turned out there is a bug here, the read-only flag is the divider's flag and hence it shall be:

 {
 	return clk_register_divider_table(NULL, name, parent_name,
-					  CLK_IS_CRITICAL |
-					  CLK_DIVIDER_READ_ONLY,
-					  reg, 16, 1, 0, mc_div_table, lock);
+					  CLK_IS_CRITICAL,
+					  reg, 16, 1, CLK_DIVIDER_READ_ONLY,
+					  mc_div_table, lock);
 }

I'll fix it up in v2.