[PATCH] clk: rockchip: Don't yell about bad mmc phases when getting

[PATCH] clk: rockchip: Don't yell about bad mmc phases when getting

[Douglas Anderson]

At boot time, my rk3288-veyron devices yell with 8 lines that look
like this:
  [    0.000000] rockchip_mmc_get_phase: invalid clk rate

This is because the clock framework at clk_register() time tries to
get the phase but we don't have a parent yet.

While the errors appear to be harmless they are still ugly and, in
general, we don't want yells like this in the log unless they are
important.

There's no real reason to be yelling here.  We can still return
-EINVAL to indicate that the phase makes no sense without a parent.
If someone really tries to do tuning and the clock is reported as 0
then we'll see the yells in rockchip_mmc_set_phase().

Fixes: 4bf59902b500 ("clk: rockchip: Prevent calculating mmc phase if clock rate is zero")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/clk/rockchip/clk-mmc-phase.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c
index 026a26bb702d..dbec84238ecd 100644
--- a/drivers/clk/rockchip/clk-mmc-phase.c
+++ b/drivers/clk/rockchip/clk-mmc-phase.c
@@ -61,10 +61,8 @@ static int rockchip_mmc_get_phase(struct clk_hw *hw)
 	u32 delay_num = 0;
 
 	/* See the comment for rockchip_mmc_set_phase below */
-	if (!rate) {
-		pr_err("%s: invalid clk rate\n", __func__);
+	if (!rate)
 		return -EINVAL;
-	}
 
 	raw_value = readl(mmc_clock->reg) >> (mmc_clock->shift);
 
-- 
2.21.0.1020.gf2820cf01a-goog

Re: [PATCH] clk: rockchip: Don't yell about bad mmc phases when getting

[Heiko Stuebner]

Am Freitag, 3. Mai 2019, 23:22:08 CEST schrieb Douglas Anderson:
> At boot time, my rk3288-veyron devices yell with 8 lines that look
> like this:
>   [    0.000000] rockchip_mmc_get_phase: invalid clk rate
> 
> This is because the clock framework at clk_register() time tries to
> get the phase but we don't have a parent yet.
> 
> While the errors appear to be harmless they are still ugly and, in
> general, we don't want yells like this in the log unless they are
> important.
> 
> There's no real reason to be yelling here.  We can still return
> -EINVAL to indicate that the phase makes no sense without a parent.
> If someone really tries to do tuning and the clock is reported as 0
> then we'll see the yells in rockchip_mmc_set_phase().
> 
> Fixes: 4bf59902b500 ("clk: rockchip: Prevent calculating mmc phase if clock rate is zero")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Thanks for fixing that. I always meant to handle that yell, but hadn't
found the time yet.

@Stephen, Mike: if you want to just apply this atop the other Rockchip
clock patches for 5.2, here is a

Reviewed-by: Heiko Stuebner <heiko@sntech.de>

Otherwise I'l queue that up for 5.3 later on.

Thanks
Heiko

> ---
> 
>  drivers/clk/rockchip/clk-mmc-phase.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c
> index 026a26bb702d..dbec84238ecd 100644
> --- a/drivers/clk/rockchip/clk-mmc-phase.c
> +++ b/drivers/clk/rockchip/clk-mmc-phase.c
> @@ -61,10 +61,8 @@ static int rockchip_mmc_get_phase(struct clk_hw *hw)
>  	u32 delay_num = 0;
>  
>  	/* See the comment for rockchip_mmc_set_phase below */
> -	if (!rate) {
> -		pr_err("%s: invalid clk rate\n", __func__);
> +	if (!rate)
>  		return -EINVAL;
> -	}
>  
>  	raw_value = readl(mmc_clock->reg) >> (mmc_clock->shift);
>  
> 

Re: [PATCH] clk: rockchip: Don't yell about bad mmc phases when getting

[Stephen Boyd]

Quoting Douglas Anderson (2019-05-03 14:22:08)
> At boot time, my rk3288-veyron devices yell with 8 lines that look
> like this:
>   [    0.000000] rockchip_mmc_get_phase: invalid clk rate
> 
> This is because the clock framework at clk_register() time tries to
> get the phase but we don't have a parent yet.
> 
> While the errors appear to be harmless they are still ugly and, in
> general, we don't want yells like this in the log unless they are
> important.
> 
> There's no real reason to be yelling here.  We can still return
> -EINVAL to indicate that the phase makes no sense without a parent.
> If someone really tries to do tuning and the clock is reported as 0
> then we'll see the yells in rockchip_mmc_set_phase().
> 
> Fixes: 4bf59902b500 ("clk: rockchip: Prevent calculating mmc phase if clock rate is zero")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---

Change looks fine, but this driver should call clk_hw_get_rate() on the
clk instead of clk_get_rate(). Unless that needs to recalc the rate for
some reason?

Also, we don't check for errors from clk_ops::get_phase() in clk.c
before storing away the result into the clk_core::phase member. I
suppose we should skip the store in this case so that debugfs results
don't look odd.

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index aa51756fd4d6..2455b2c43386 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2606,14 +2606,14 @@ EXPORT_SYMBOL_GPL(clk_set_phase);
 
 static int clk_core_get_phase(struct clk_core *core)
 {
-	int ret;
+	int ret = 0;
 
-	clk_prepare_lock();
+	lockdep_assert_held(&prepare_lock);
 	/* Always try to update cached phase if possible */
 	if (core->ops->get_phase)
-		core->phase = core->ops->get_phase(core->hw);
-	ret = core->phase;
-	clk_prepare_unlock();
+		ret = core->ops->get_phase(core->hw);
+	if (ret >= 0)
+		core->phase = ret;
 
 	return ret;
 }
@@ -2627,10 +2627,16 @@ static int clk_core_get_phase(struct clk_core *core)
  */
 int clk_get_phase(struct clk *clk)
 {
+	int ret;
+
 	if (!clk)
 		return 0;
 
-	return clk_core_get_phase(clk->core);
+	clk_prepare_unlock();
+	ret = clk_core_get_phase(clk->core);
+	clk_prepare_unlock();
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(clk_get_phase);
 
@@ -2850,16 +2856,24 @@ static struct hlist_head *orphan_list[] = {
 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
 				 int level)
 {
+	int phase;
+
 	if (!c)
 		return;
 
-	seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
+	seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
 		   level * 3 + 1, "",
 		   30 - level * 3, c->name,
 		   c->enable_count, c->prepare_count, c->protect_count,
-		   clk_core_get_rate(c), clk_core_get_accuracy(c),
-		   clk_core_get_phase(c),
-		   clk_core_get_scaled_duty_cycle(c, 100000));
+		   clk_core_get_rate(c), clk_core_get_accuracy(c));
+
+	phase = clk_core_get_phase(c);
+	if (phase >= 0)
+		seq_printf(s, "%5d", phase);
+	else
+		seq_printf(s, "-----");
+
+	seq_printf(s, " %6d\n", clk_core_get_scaled_duty_cycle(c, 100000));
 }
 
 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
@@ -2899,6 +2913,8 @@ DEFINE_SHOW_ATTRIBUTE(clk_summary);
 
 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
 {
+	int phase;
+
 	if (!c)
 		return;
 
@@ -2909,7 +2925,9 @@ static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
 	seq_printf(s, "\"protect_count\": %d,", c->protect_count);
 	seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
 	seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
-	seq_printf(s, "\"phase\": %d,", clk_core_get_phase(c));
+	phase = clk_core_get_phase(c);
+	if (phase >= 0)
+		seq_printf(s, "\"phase\": %d,", phase);
 	seq_printf(s, "\"duty_cycle\": %u",
 		   clk_core_get_scaled_duty_cycle(c, 100000));
 }
@@ -3248,10 +3266,7 @@ static int __clk_core_init(struct clk_core *core)
 	 * Since a phase is by definition relative to its parent, just
 	 * query the current clock phase, or just assume it's in phase.
 	 */
-	if (core->ops->get_phase)
-		core->phase = core->ops->get_phase(core->hw);
-	else
-		core->phase = 0;
+	clk_core_get_phase(core);
 
 	/*
 	 * Set clk's duty cycle.

Re: [PATCH] clk: rockchip: Don't yell about bad mmc phases when getting

[Heiko Stuebner]

Am Freitag, 3. Mai 2019, 23:22:08 CEST schrieb Douglas Anderson:
> At boot time, my rk3288-veyron devices yell with 8 lines that look
> like this:
>   [    0.000000] rockchip_mmc_get_phase: invalid clk rate
> 
> This is because the clock framework at clk_register() time tries to
> get the phase but we don't have a parent yet.
> 
> While the errors appear to be harmless they are still ugly and, in
> general, we don't want yells like this in the log unless they are
> important.
> 
> There's no real reason to be yelling here.  We can still return
> -EINVAL to indicate that the phase makes no sense without a parent.
> If someone really tries to do tuning and the clock is reported as 0
> then we'll see the yells in rockchip_mmc_set_phase().
> 
> Fixes: 4bf59902b500 ("clk: rockchip: Prevent calculating mmc phase if clock rate is zero")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

applied for 5.3

Thanks
Heiko