Tony,
On 09/23/2015 12:23 AM, Tony Lindgren wrote:
> As recently pointed out (again) by Thomas and Russell, we must not
> wait in in clk_enable. The wait for PLL to lock needs to happen
> in clk_prepare instead.
>
> It seems this is a common copy paste error with the PLL drivers,
> and similar fixes should be applied to other PLL drivers after
> testing.
One thing to note:
because of how the hwmod code works, at boot time we prepare all clocks for
the devices and in runtime the hwmod only uses clk_enable/disable, it will
never unprepare the clock(s). This will means that these clocks will be
enabled all the time and will never turned off.
--
Péter
> Cc: Brian Hutchinson <b.hutchman@xxxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Cc: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Cc: Nishanth Menon <nm@xxxxxx>
> Cc: Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Sekhar Nori <nsekhar@xxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/clk/ti/fapll.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/clk/ti/fapll.c b/drivers/clk/ti/fapll.c
> index f4b2e98..e1db74a 100644
> --- a/drivers/clk/ti/fapll.c
> +++ b/drivers/clk/ti/fapll.c
> @@ -37,7 +37,7 @@
> #define FAPLL_PWD_OFFSET 4
>
> #define MAX_FAPLL_OUTPUTS 7
> -#define FAPLL_MAX_RETRIES 1000
> +#define FAPLL_MAX_RETRIES 5
>
> #define to_fapll(_hw) container_of(_hw, struct fapll_data, hw)
> #define to_synth(_hw) container_of(_hw, struct fapll_synth, hw)
> @@ -126,7 +126,7 @@ static int ti_fapll_wait_lock(struct fapll_data *fd)
> if (retries-- <= 0)
> break;
>
> - udelay(1);
> + usleep_range(200, 300);
> }
>
> pr_err("%s failed to lock\n", fd->name);
> @@ -134,7 +134,7 @@ static int ti_fapll_wait_lock(struct fapll_data *fd)
> return -ETIMEDOUT;
> }
>
> -static int ti_fapll_enable(struct clk_hw *hw)
> +static int ti_fapll_prepare(struct clk_hw *hw)
> {
> struct fapll_data *fd = to_fapll(hw);
> u32 v = readl_relaxed(fd->base);
> @@ -146,7 +146,7 @@ static int ti_fapll_enable(struct clk_hw *hw)
> return 0;
> }
>
> -static void ti_fapll_disable(struct clk_hw *hw)
> +static void ti_fapll_unprepare(struct clk_hw *hw)
> {
> struct fapll_data *fd = to_fapll(hw);
> u32 v = readl_relaxed(fd->base);
> @@ -155,7 +155,7 @@ static void ti_fapll_disable(struct clk_hw *hw)
> writel_relaxed(v, fd->base);
> }
>
> -static int ti_fapll_is_enabled(struct clk_hw *hw)
> +static int ti_fapll_is_prepared(struct clk_hw *hw)
> {
> struct fapll_data *fd = to_fapll(hw);
> u32 v = readl_relaxed(fd->base);
> @@ -261,7 +261,7 @@ static int ti_fapll_set_rate(struct clk_hw *hw, unsigned long rate,
> v |= pre_div_p << FAPLL_MAIN_DIV_P_SHIFT;
> v |= mult_n << FAPLL_MAIN_MULT_N_SHIFT;
> writel_relaxed(v, fd->base);
> - if (ti_fapll_is_enabled(hw))
> + if (ti_fapll_is_prepared(hw))
> ti_fapll_wait_lock(fd);
> ti_fapll_clear_bypass(fd);
>
> @@ -269,9 +269,9 @@ static int ti_fapll_set_rate(struct clk_hw *hw, unsigned long rate,
> }
>
> static struct clk_ops ti_fapll_ops = {
> - .enable = ti_fapll_enable,
> - .disable = ti_fapll_disable,
> - .is_enabled = ti_fapll_is_enabled,
> + .prepare = ti_fapll_prepare,
> + .unprepare = ti_fapll_unprepare,
> + .is_prepared = ti_fapll_is_prepared,
> .recalc_rate = ti_fapll_recalc_rate,
> .get_parent = ti_fapll_get_parent,
> .round_rate = ti_fapll_round_rate,
>
--
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