Re: [PATCH] clk/at91: Hold reference returned by of_get_parent()

Claudiu.Beznea
2022-06-27T10:36:14Z

On 27.06.2022 13:32, Liang He wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> At 2022-06-27 17:05:18, Claudiu.Beznea@microchip.com wrote:
>> Hi, Liang,
>>
>> Patch title should be something like "clk: at91: dt-compat: <you message>"
>>
>
> Thanks, I am preparing the version-2 patch code and I will change all similar clk bugs commit title
> using above format.
>
>>
>> On 24.06.2022 13:59, Liang He wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>
>>> We need to hold the reference returned by of_get_parent() and use
>>> it to call of_node_put() for refcount balance.
>>>
>>> Fixes: 62061d357c7f ("clk: at91: move DT compatibility code to its own file")
>>> Signed-off-by: Liang He <windhl@126.com>
>>> ---
>>> these bugs are found in 5.19rc2
>>> these bugs are confirmed not fixed by lore.kernel.org
>>> these bugs are compiled tested in 5.19rc2 with at91_dt_defconfig
>>>
>>> drivers/clk/at91/dt-compat.c | 108 +++++++++++++++++++++++++++--------
>>> 1 file changed, 84 insertions(+), 24 deletions(-)
>>>
>>> diff --git a/drivers/clk/at91/dt-compat.c b/drivers/clk/at91/dt-compat.c
>>> index 8ca8bcacf66d..cc34141864bd 100644
>>> --- a/drivers/clk/at91/dt-compat.c
>>> +++ b/drivers/clk/at91/dt-compat.c
>>> @@ -33,8 +33,11 @@ static void __init of_sama5d2_clk_audio_pll_frac_setup(struct device_node *np)
>>> const char *name = np->name;
>>> const char *parent_name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>
>> What tp stands for?
>
> I only want to use it to mean 'tmp_pointer', but Martin advises to
> use 'parent_np'.
>
> I will chose to use 'parent_np' in my version-2 patch, and how do you
> think about this name?

parent_np is good.

Thank you,
Claudiu Beznea

>
> Thanks very much for reviewing my patch code.
>
> Liang
>>
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -56,8 +59,11 @@ static void __init of_sama5d2_clk_audio_pll_pad_setup(struct device_node *np)
>>> const char *name = np->name;
>>> const char *parent_name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -79,8 +85,11 @@ static void __init of_sama5d2_clk_audio_pll_pmc_setup(struct device_node *np)
>>> const char *name = np->name;
>>> const char *parent_name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -120,7 +129,7 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
>>> struct clk_hw *hw;
>>> unsigned int num_parents;
>>> const char *parent_names[GENERATED_SOURCE_MAX];
>>> - struct device_node *gcknp;
>>> + struct device_node *gcknp, *tp;
>>> struct clk_range range = CLK_RANGE(0, 0);
>>> struct regmap *regmap;
>>>
>>> @@ -134,7 +143,9 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
>>> if (!num || num > PERIPHERAL_MAX)
>>> return;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -180,8 +191,11 @@ static void __init of_sama5d4_clk_h32mx_setup(struct device_node *np)
>>> const char *name = np->name;
>>> const char *parent_name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -243,12 +257,15 @@ static void __init of_at91rm9200_clk_main_osc_setup(struct device_node *np)
>>> const char *parent_name;
>>> struct regmap *regmap;
>>> bool bypass;
>>> + struct device_node *tp;
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>> bypass = of_property_read_bool(np, "atmel,osc-bypass");
>>> parent_name = of_clk_get_parent_name(np, 0);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -268,12 +285,15 @@ static void __init of_at91sam9x5_clk_main_rc_osc_setup(struct device_node *np)
>>> u32 accuracy = 0;
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>> of_property_read_u32(np, "clock-frequency", &frequency);
>>> of_property_read_u32(np, "clock-accuracy", &accuracy);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -292,11 +312,14 @@ static void __init of_at91rm9200_clk_main_setup(struct device_node *np)
>>> const char *parent_name;
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> parent_name = of_clk_get_parent_name(np, 0);
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -316,13 +339,16 @@ static void __init of_at91sam9x5_clk_main_setup(struct device_node *np)
>>> unsigned int num_parents;
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> num_parents = of_clk_get_parent_count(np);
>>> if (num_parents == 0 || num_parents > 2)
>>> return;
>>>
>>> of_clk_parent_fill(np, parent_names, num_parents);
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -373,6 +399,7 @@ of_at91_clk_master_setup(struct device_node *np,
>>> const char *name = np->name;
>>> struct clk_master_characteristics *characteristics;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> num_parents = of_clk_get_parent_count(np);
>>> if (num_parents == 0 || num_parents > MASTER_SOURCE_MAX)
>>> @@ -386,7 +413,9 @@ of_at91_clk_master_setup(struct device_node *np,
>>> if (!characteristics)
>>> return;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -433,6 +462,7 @@ of_at91_clk_periph_setup(struct device_node *np, u8 type)
>>> const char *name;
>>> struct device_node *periphclknp;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> parent_name = of_clk_get_parent_name(np, 0);
>>> if (!parent_name)
>>> @@ -442,7 +472,9 @@ of_at91_clk_periph_setup(struct device_node *np, u8 type)
>>> if (!num || num > PERIPHERAL_MAX)
>>> return;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -602,6 +634,7 @@ of_at91_clk_pll_setup(struct device_node *np,
>>> const char *parent_name;
>>> const char *name = np->name;
>>> struct clk_pll_characteristics *characteristics;
>>> + struct device_node *tp;
>>>
>>> if (of_property_read_u32(np, "reg", &id))
>>> return;
>>> @@ -610,7 +643,9 @@ of_at91_clk_pll_setup(struct device_node *np,
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -665,12 +700,15 @@ of_at91sam9x5_clk_plldiv_setup(struct device_node *np)
>>> const char *parent_name;
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> parent_name = of_clk_get_parent_name(np, 0);
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -694,7 +732,7 @@ of_at91_clk_prog_setup(struct device_node *np,
>>> unsigned int num_parents;
>>> const char *parent_names[PROG_SOURCE_MAX];
>>> const char *name;
>>> - struct device_node *progclknp;
>>> + struct device_node *progclknp, *tp;
>>> struct regmap *regmap;
>>>
>>> num_parents = of_clk_get_parent_count(np);
>>> @@ -707,7 +745,9 @@ of_at91_clk_prog_setup(struct device_node *np,
>>> if (!num || num > (PROG_ID_MAX + 1))
>>> return;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -756,13 +796,16 @@ static void __init of_at91sam9260_clk_slow_setup(struct device_node *np)
>>> unsigned int num_parents;
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> num_parents = of_clk_get_parent_count(np);
>>> if (num_parents != 2)
>>> return;
>>>
>>> of_clk_parent_fill(np, parent_names, num_parents);
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -788,6 +831,7 @@ static void __init of_at91sam9x5_clk_smd_setup(struct device_node *np)
>>> const char *parent_names[SMD_SOURCE_MAX];
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> num_parents = of_clk_get_parent_count(np);
>>> if (num_parents == 0 || num_parents > SMD_SOURCE_MAX)
>>> @@ -797,7 +841,9 @@ static void __init of_at91sam9x5_clk_smd_setup(struct device_node *np)
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -818,7 +864,7 @@ static void __init of_at91rm9200_clk_sys_setup(struct device_node *np)
>>> u32 id;
>>> struct clk_hw *hw;
>>> const char *name;
>>> - struct device_node *sysclknp;
>>> + struct device_node *sysclknp, *tp;
>>> const char *parent_name;
>>> struct regmap *regmap;
>>>
>>> @@ -826,7 +872,9 @@ static void __init of_at91rm9200_clk_sys_setup(struct device_node *np)
>>> if (num > (SYSTEM_MAX_ID + 1))
>>> return;
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -859,6 +907,7 @@ static void __init of_at91sam9x5_clk_usb_setup(struct device_node *np)
>>> const char *parent_names[USB_SOURCE_MAX];
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> num_parents = of_clk_get_parent_count(np);
>>> if (num_parents == 0 || num_parents > USB_SOURCE_MAX)
>>> @@ -868,7 +917,9 @@ static void __init of_at91sam9x5_clk_usb_setup(struct device_node *np)
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -888,6 +939,7 @@ static void __init of_at91sam9n12_clk_usb_setup(struct device_node *np)
>>> const char *parent_name;
>>> const char *name = np->name;
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> parent_name = of_clk_get_parent_name(np, 0);
>>> if (!parent_name)
>>> @@ -895,7 +947,9 @@ static void __init of_at91sam9n12_clk_usb_setup(struct device_node *np)
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>>
>>> @@ -915,6 +969,7 @@ static void __init of_at91rm9200_clk_usb_setup(struct device_node *np)
>>> const char *name = np->name;
>>> u32 divisors[4] = {0, 0, 0, 0};
>>> struct regmap *regmap;
>>> + struct device_node *tp;
>>>
>>> parent_name = of_clk_get_parent_name(np, 0);
>>> if (!parent_name)
>>> @@ -926,7 +981,9 @@ static void __init of_at91rm9200_clk_usb_setup(struct device_node *np)
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap))
>>> return;
>>> hw = at91rm9200_clk_register_usb(regmap, name, parent_name, divisors);
>>> @@ -946,12 +1003,15 @@ static void __init of_at91sam9x5_clk_utmi_setup(struct device_node *np)
>>> const char *parent_name;
>>> const char *name = np->name;
>>> struct regmap *regmap_pmc, *regmap_sfr;
>>> + struct device_node *tp;
>>>
>>> parent_name = of_clk_get_parent_name(np, 0);
>>>
>>> of_property_read_string(np, "clock-output-names", &name);
>>>
>>> - regmap_pmc = syscon_node_to_regmap(of_get_parent(np));
>>> + tp = of_get_parent(np);
>>> + regmap_pmc = syscon_node_to_regmap(tp);
>>> + of_node_put(tp);
>>> if (IS_ERR(regmap_pmc))
>>> return;
>>>
>>> --
>>> 2.25.1
>>>
>>