diff mbox series

[1/7] clk: actions: Fix factor clk struct member access

Message ID 20190608195317.6336-2-manivannan.sadhasivam@linaro.org (mailing list archive)
State New, archived
Headers show
Series Add SD/MMC driver for Actions Semi S900 SoC | expand

Commit Message

Manivannan Sadhasivam June 8, 2019, 7:53 p.m. UTC
Since the helper "owl_factor_helper_round_rate" is shared between factor
and composite clocks, using the factor clk specific helper function
like "hw_to_owl_factor" to access its members will create issues when
called from composite clk specific code. Hence, pass the "factor_hw"
struct pointer directly instead of fetching it using factor clk specific
helpers.

This issue has been observed when a composite clock like "sd0_clk" tried
to call "owl_factor_helper_round_rate" resulting in pointer dereferencing
error.

Fixes: 4bb78fc9744a ("clk: actions: Add factor clock support")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/clk/actions/owl-factor.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Comments

Andreas Färber June 10, 2019, 1:36 p.m. UTC | #1
Hi Mani,

Am 08.06.19 um 21:53 schrieb Manivannan Sadhasivam:
> Since the helper "owl_factor_helper_round_rate" is shared between factor
> and composite clocks, using the factor clk specific helper function
> like "hw_to_owl_factor" to access its members will create issues when
> called from composite clk specific code. Hence, pass the "factor_hw"
> struct pointer directly instead of fetching it using factor clk specific
> helpers.
> 
> This issue has been observed when a composite clock like "sd0_clk" tried
> to call "owl_factor_helper_round_rate" resulting in pointer dereferencing
> error.
> 
> Fixes: 4bb78fc9744a ("clk: actions: Add factor clock support")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/clk/actions/owl-factor.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/actions/owl-factor.c b/drivers/clk/actions/owl-factor.c
> index 317d4a9e112e..f419dfdd334f 100644
> --- a/drivers/clk/actions/owl-factor.c
> +++ b/drivers/clk/actions/owl-factor.c
> @@ -64,11 +64,10 @@ static unsigned int _get_table_val(const struct clk_factor_table *table,
>  	return val;
>  }
>  
> -static int clk_val_best(struct clk_hw *hw, unsigned long rate,
> +static int clk_val_best(const struct owl_factor_hw *factor_hw,
> +			struct clk_hw *hw, unsigned long rate,
>  			unsigned long *best_parent_rate)
>  {
> -	struct owl_factor *factor = hw_to_owl_factor(hw);
> -	struct owl_factor_hw *factor_hw = &factor->factor_hw;
>  	const struct clk_factor_table *clkt = factor_hw->table;
>  	unsigned long parent_rate, try_parent_rate, best = 0, cur_rate;
>  	unsigned long parent_rate_saved = *best_parent_rate;
> @@ -126,7 +125,7 @@ long owl_factor_helper_round_rate(struct owl_clk_common *common,
>  	const struct clk_factor_table *clkt = factor_hw->table;
>  	unsigned int val, mul = 0, div = 1;
>  
> -	val = clk_val_best(&common->hw, rate, parent_rate);
> +	val = clk_val_best(factor_hw, &common->hw, rate, parent_rate);
>  	_get_table_div_mul(clkt, val, &mul, &div);
>  
>  	return *parent_rate * mul / div;

While at it, I think it would be a good idea to rename it to
owl_clk_val_best. Pretty confusing that you're touching only owl files
for a clk_ refactoring, which sounds like common clk code.

Regards,
Andreas
Stephen Boyd June 10, 2019, 3:01 p.m. UTC | #2
Quoting Manivannan Sadhasivam (2019-06-08 12:53:11)
> Since the helper "owl_factor_helper_round_rate" is shared between factor
> and composite clocks, using the factor clk specific helper function
> like "hw_to_owl_factor" to access its members will create issues when
> called from composite clk specific code. Hence, pass the "factor_hw"
> struct pointer directly instead of fetching it using factor clk specific
> helpers.
> 
> This issue has been observed when a composite clock like "sd0_clk" tried
> to call "owl_factor_helper_round_rate" resulting in pointer dereferencing
> error.
> 
> Fixes: 4bb78fc9744a ("clk: actions: Add factor clock support")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---

I agree with Andreas on the function name. With that change you can add

Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Manivannan Sadhasivam June 10, 2019, 4:05 p.m. UTC | #3
Hi Andreas,

On Mon, Jun 10, 2019 at 03:36:42PM +0200, Andreas Färber wrote:
> Hi Mani,
> 
> Am 08.06.19 um 21:53 schrieb Manivannan Sadhasivam:
> > Since the helper "owl_factor_helper_round_rate" is shared between factor
> > and composite clocks, using the factor clk specific helper function
> > like "hw_to_owl_factor" to access its members will create issues when
> > called from composite clk specific code. Hence, pass the "factor_hw"
> > struct pointer directly instead of fetching it using factor clk specific
> > helpers.
> > 
> > This issue has been observed when a composite clock like "sd0_clk" tried
> > to call "owl_factor_helper_round_rate" resulting in pointer dereferencing
> > error.
> > 
> > Fixes: 4bb78fc9744a ("clk: actions: Add factor clock support")
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  drivers/clk/actions/owl-factor.c | 7 +++----
> >  1 file changed, 3 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/clk/actions/owl-factor.c b/drivers/clk/actions/owl-factor.c
> > index 317d4a9e112e..f419dfdd334f 100644
> > --- a/drivers/clk/actions/owl-factor.c
> > +++ b/drivers/clk/actions/owl-factor.c
> > @@ -64,11 +64,10 @@ static unsigned int _get_table_val(const struct clk_factor_table *table,
> >  	return val;
> >  }
> >  
> > -static int clk_val_best(struct clk_hw *hw, unsigned long rate,
> > +static int clk_val_best(const struct owl_factor_hw *factor_hw,
> > +			struct clk_hw *hw, unsigned long rate,
> >  			unsigned long *best_parent_rate)
> >  {
> > -	struct owl_factor *factor = hw_to_owl_factor(hw);
> > -	struct owl_factor_hw *factor_hw = &factor->factor_hw;
> >  	const struct clk_factor_table *clkt = factor_hw->table;
> >  	unsigned long parent_rate, try_parent_rate, best = 0, cur_rate;
> >  	unsigned long parent_rate_saved = *best_parent_rate;
> > @@ -126,7 +125,7 @@ long owl_factor_helper_round_rate(struct owl_clk_common *common,
> >  	const struct clk_factor_table *clkt = factor_hw->table;
> >  	unsigned int val, mul = 0, div = 1;
> >  
> > -	val = clk_val_best(&common->hw, rate, parent_rate);
> > +	val = clk_val_best(factor_hw, &common->hw, rate, parent_rate);
> >  	_get_table_div_mul(clkt, val, &mul, &div);
> >  
> >  	return *parent_rate * mul / div;
> 
> While at it, I think it would be a good idea to rename it to
> owl_clk_val_best. Pretty confusing that you're touching only owl files
> for a clk_ refactoring, which sounds like common clk code.
> 

Sure, will do.

Thanks,
Mani

> Regards,
> Andreas
> 
> -- 
> SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
> HRB 21284 (AG Nürnberg)
diff mbox series

Patch

diff --git a/drivers/clk/actions/owl-factor.c b/drivers/clk/actions/owl-factor.c
index 317d4a9e112e..f419dfdd334f 100644
--- a/drivers/clk/actions/owl-factor.c
+++ b/drivers/clk/actions/owl-factor.c
@@ -64,11 +64,10 @@  static unsigned int _get_table_val(const struct clk_factor_table *table,
 	return val;
 }
 
-static int clk_val_best(struct clk_hw *hw, unsigned long rate,
+static int clk_val_best(const struct owl_factor_hw *factor_hw,
+			struct clk_hw *hw, unsigned long rate,
 			unsigned long *best_parent_rate)
 {
-	struct owl_factor *factor = hw_to_owl_factor(hw);
-	struct owl_factor_hw *factor_hw = &factor->factor_hw;
 	const struct clk_factor_table *clkt = factor_hw->table;
 	unsigned long parent_rate, try_parent_rate, best = 0, cur_rate;
 	unsigned long parent_rate_saved = *best_parent_rate;
@@ -126,7 +125,7 @@  long owl_factor_helper_round_rate(struct owl_clk_common *common,
 	const struct clk_factor_table *clkt = factor_hw->table;
 	unsigned int val, mul = 0, div = 1;
 
-	val = clk_val_best(&common->hw, rate, parent_rate);
+	val = clk_val_best(factor_hw, &common->hw, rate, parent_rate);
 	_get_table_div_mul(clkt, val, &mul, &div);
 
 	return *parent_rate * mul / div;