[PATCH] clk: qcom: Don't overwrite 'cfg' in clk_rcg2_dfs_populate_freq()

[PATCH] clk: qcom: Don't overwrite 'cfg' in clk_rcg2_dfs_populate_freq()

[Stephen Boyd]

The DFS frequency table logic overwrites 'cfg' while detecting the
parent clk and then later on in clk_rcg2_dfs_populate_freq() we use that
same variable to figure out the mode of the clk, either MND or not. Add
a new variable to hold the parent clk bit so that 'cfg' is left
untouched for use later.

This fixes problems in detecting the supported frequencies for any clks
in DFS mode.

Fixes: cc4f6944d0e3 ("clk: qcom: Add support for RCG to register for DFS")
Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
---
 drivers/clk/qcom/clk-rcg2.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index da045b200def..973ecf4f6bc5 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -953,7 +953,7 @@ static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
 	struct clk_hw *p;
 	unsigned long prate = 0;
-	u32 val, mask, cfg, mode;
+	u32 val, mask, cfg, mode, src;
 	int i, num_parents;
 
 	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + SE_PERF_DFSR(l), &cfg);
@@ -963,12 +963,12 @@ static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
 	if (cfg & mask)
 		f->pre_div = cfg & mask;
 
-	cfg &= CFG_SRC_SEL_MASK;
-	cfg >>= CFG_SRC_SEL_SHIFT;
+	src = cfg & CFG_SRC_SEL_MASK;
+	src >>= CFG_SRC_SEL_SHIFT;
 
 	num_parents = clk_hw_get_num_parents(hw);
 	for (i = 0; i < num_parents; i++) {
-		if (cfg == rcg->parent_map[i].cfg) {
+		if (src == rcg->parent_map[i].cfg) {
 			f->src = rcg->parent_map[i].src;
 			p = clk_hw_get_parent_by_index(&rcg->clkr.hw, i);
 			prate = clk_hw_get_rate(p);
-- 
Sent by a computer, using git, on the internet

Re: [PATCH] clk: qcom: Don't overwrite 'cfg' in clk_rcg2_dfs_populate_freq()

[Rajendra Nayak]

On 1/29/2020 1:03 AM, Stephen Boyd wrote:
> The DFS frequency table logic overwrites 'cfg' while detecting the
> parent clk and then later on in clk_rcg2_dfs_populate_freq() we use that
> same variable to figure out the mode of the clk, either MND or not. Add
> a new variable to hold the parent clk bit so that 'cfg' is left
> untouched for use later.
> 
> This fixes problems in detecting the supported frequencies for any clks
> in DFS mode.
> 
> Fixes: cc4f6944d0e3 ("clk: qcom: Add support for RCG to register for DFS")
> Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
> ---

Tested-by: Rajendra Nayak <rnayak@codeaurora.org>

>   drivers/clk/qcom/clk-rcg2.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
> index da045b200def..973ecf4f6bc5 100644
> --- a/drivers/clk/qcom/clk-rcg2.c
> +++ b/drivers/clk/qcom/clk-rcg2.c
> @@ -953,7 +953,7 @@ static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
>   	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
>   	struct clk_hw *p;
>   	unsigned long prate = 0;
> -	u32 val, mask, cfg, mode;
> +	u32 val, mask, cfg, mode, src;
>   	int i, num_parents;
>   
>   	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + SE_PERF_DFSR(l), &cfg);
> @@ -963,12 +963,12 @@ static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
>   	if (cfg & mask)
>   		f->pre_div = cfg & mask;
>   
> -	cfg &= CFG_SRC_SEL_MASK;
> -	cfg >>= CFG_SRC_SEL_SHIFT;
> +	src = cfg & CFG_SRC_SEL_MASK;
> +	src >>= CFG_SRC_SEL_SHIFT;
>   
>   	num_parents = clk_hw_get_num_parents(hw);
>   	for (i = 0; i < num_parents; i++) {
> -		if (cfg == rcg->parent_map[i].cfg) {
> +		if (src == rcg->parent_map[i].cfg) {
>   			f->src = rcg->parent_map[i].src;
>   			p = clk_hw_get_parent_by_index(&rcg->clkr.hw, i);
>   			prate = clk_hw_get_rate(p);
> 

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH] clk: qcom: Don't overwrite 'cfg' in clk_rcg2_dfs_populate_freq()

[Stephen Boyd]

Quoting Stephen Boyd (2020-01-28 11:33:29)
> The DFS frequency table logic overwrites 'cfg' while detecting the
> parent clk and then later on in clk_rcg2_dfs_populate_freq() we use that
> same variable to figure out the mode of the clk, either MND or not. Add
> a new variable to hold the parent clk bit so that 'cfg' is left
> untouched for use later.
> 
> This fixes problems in detecting the supported frequencies for any clks
> in DFS mode.
> 
> Fixes: cc4f6944d0e3 ("clk: qcom: Add support for RCG to register for DFS")
> Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
> ---

Applied to clk-next