On 01.04.2021 17:42, Claudiu Beznea - M18063 wrote:
> On 31.03.2021 11:18, Nicolas Ferre wrote:
>> On 09/02/2021 at 12:01, Claudiu Beznea wrote:
>>> Free resources on exit path (failure path of probe and remove).
>>
>> I'm not sure we can use this driver as a module anyway.
>>
>> Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(),
>> even in loop, and avoid having to deal with exit path?
>
> For:
> reset->rstc_base = of_iomap(pdev->dev.of_node, 0);
>
> it should work.
>
> For the maps in the loop I have to double check. Basically, the struct
> resource object to pass to devm_of_iomap() is needed and for this the
Just realized I looked at the wrong code. Anyway, I'll double check and return.
> pointer to a struct platform_device object corresponding to the node we
> look for in the loop is needed. So, I think this cannot be done this way.
>
>>
>>> Reported-by: kernel test robot <l...@intel.com>
>>> Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
>>> Signed-off-by: Claudiu Beznea <claudiu.bez...@microchip.com>
>>> ---
>>> drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>>> 1 file changed, 20 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/power/reset/at91-reset.c
>>> b/drivers/power/reset/at91-reset.c
>>> index 3ff9d93a5226..2ff7833153b6 100644
>>> --- a/drivers/power/reset/at91-reset.c
>>> +++ b/drivers/power/reset/at91-reset.c
>>> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>> if (!reset->ramc_base[idx]) {
>>> dev_err(&pdev->dev, "Could not map ram controller
>>> address\n");
>>> of_node_put(np);
>>> - return -ENODEV;
>>> + ret = -ENODEV;
>>> + goto unmap;
>>> }
>>> idx++;
>>> }
>>> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>> reset->args = (u32)match->data;
>>> reset->sclk = devm_clk_get(&pdev->dev, NULL);
>>> - if (IS_ERR(reset->sclk))
>>> - return PTR_ERR(reset->sclk);
>>> + if (IS_ERR(reset->sclk)) {
>>> + ret = PTR_ERR(reset->sclk);
>>> + goto unmap;
>>> + }
>>> ret = clk_prepare_enable(reset->sclk);
>>> if (ret) {
>>> dev_err(&pdev->dev, "Could not enable slow clock\n");
>>> - return ret;
>>> + goto unmap;
>>> }
>>> platform_set_drvdata(pdev, reset);
>>> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>> ret = register_restart_handler(&reset->nb);
>>> if (ret) {
>>> clk_disable_unprepare(reset->sclk);
>>> - return ret;
>>> + goto unmap;
>>> }
>>> at91_reset_status(pdev, reset->rstc_base);
>>> return 0;
>>> +
>>> +unmap:
>>> + iounmap(reset->rstc_base);
>>> + for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> + iounmap(reset->ramc_base[idx]);
>>
>> But if we keep this loop, I have the feeling that some kind of
>> "of_node_put()" is needed as well.
>
> No! In the loop:
>
> for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
> reset->ramc_lpr = (u32)match->data;
> reset->ramc_base[idx] = of_iomap(np, 0);
> if (!reset->ramc_base[idx]) {
> dev_err(&pdev->dev, "Could not map ram controller address\n");
> of_node_put(np);
> ret = -ENODEV;
> goto unmap;
> }
> idx++;
> }
>
> the of_node_put() is needed only if the loop is interrupted as the macro:
> for_each_matching_node_and_match() is defined as follows:
>
> #define for_each_matching_node_and_match(dn, matches, match) \
> for (dn = of_find_matching_node_and_match(NULL, matches, match); \
> dn; dn = of_find_matching_node_and_match(dn, matches, match))
>
> and of_find_matching_node_and_match() will return a np with refcount
> incremented but at the next loop step the of_find_matching_node_and_match()
> will be called with the same np pointer and the np refcount will be
> decremented.
>
> struct device_node *of_find_matching_node_and_match(
> struct device_node *from,
> const struct of_device_id *matches,
> const struct of_device_id **match)
> {
> // ...
> of_node_put(from);
> // ...
> }
>
>>
>>> +
>>> + return ret;
>>> }
>>> static int __exit at91_reset_remove(struct platform_device *pdev)
>>> {
>>> struct at91_reset *reset = platform_get_drvdata(pdev);
>>> + int idx;
>>> unregister_restart_handler(&reset->nb);
>>> clk_disable_unprepare(reset->sclk);
>>> + iounmap(reset->rstc_base);
>>> + for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> + iounmap(reset->ramc_base[idx]);
>>
>> Ditto
>>
>>> +
>>> return 0;
>>> }
>>>
>>
>>
>
