At 2022-06-17 13:37:12, "Christophe JAILLET" <christophe.jail...@wanadoo.fr> wrote: >Le 17/06/2022 à 07:22, Liang He a écrit : >> In gpio_halt_probe(), of_find_matching_node() will return a node >> pointer with refcount incremented. We should use of_node_put() in >> fail path or when it is not used anymore. >> >> Signed-off-by: Liang He <win...@126.com> >> --- >> arch/powerpc/platforms/85xx/sgy_cts1000.c | 39 +++++++++++++++-------- >> 1 file changed, 25 insertions(+), 14 deletions(-) >> >> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c >> b/arch/powerpc/platforms/85xx/sgy_cts1000.c >> index 98ae64075193..a8690fc552cf 100644 >> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >> @@ -71,33 +71,39 @@ static int gpio_halt_probe(struct platform_device *pdev) >> { >> enum of_gpio_flags flags; >> struct device_node *node = pdev->dev.of_node; >> + struct device_node *child_node; >> int gpio, err, irq; >> int trigger; >> + int ret; >> >> if (!node) >> return -ENODEV; >> >> /* If there's no matching child, this isn't really an error */ >> - halt_node = of_find_matching_node(node, child_match); >> - if (!halt_node) >> + child_node = of_find_matching_node(node, child_match); >> + if (!child_node) >> return 0; >> >> /* Technically we could just read the first one, but punish >> * DT writers for invalid form. */ >> - if (of_gpio_count(halt_node) != 1) >> - return -EINVAL; >> + if (of_gpio_count(child_node) != 1) { >> + ret = -EINVAL; >> + goto err_put; >> + } >> >> /* Get the gpio number relative to the dynamic base. */ >> - gpio = of_get_gpio_flags(halt_node, 0, &flags); >> - if (!gpio_is_valid(gpio)) >> - return -EINVAL; >> + gpio = of_get_gpio_flags(child_node, 0, &flags); >> + if (!gpio_is_valid(gpio)) { >> + ret = -EINVAL; >> + gotot err_put; >> + } >> >> err = gpio_request(gpio, "gpio-halt"); >> if (err) { >> printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n", >> gpio); >> - halt_node = NULL; >> - return err; >> + ret = err; > >Sorry for not seeing and asking before, but why do you need 'ret'? >Can't you use the existing 'err' in place in this whole patch? >
Thanks, CJ. Your advice is good and I have not noticed the 'err'. >> + goto err_put; >> } >> >> trigger = (flags == OF_GPIO_ACTIVE_LOW); >> @@ -105,15 +111,15 @@ static int gpio_halt_probe(struct platform_device >> *pdev) >> gpio_direction_output(gpio, !trigger); >> >> /* Now get the IRQ which tells us when the power button is hit */ >> - irq = irq_of_parse_and_map(halt_node, 0); >> + irq = irq_of_parse_and_map(child_node, 0); >> err = request_irq(irq, gpio_halt_irq, IRQF_TRIGGER_RISING | >> - IRQF_TRIGGER_FALLING, "gpio-halt", halt_node); >> + IRQF_TRIGGER_FALLING, "gpio-halt", child_node); >> if (err) { >> printk(KERN_ERR "gpio-halt: error requesting IRQ %d for " >> "GPIO %d.\n", irq, gpio); >> gpio_free(gpio); >> - halt_node = NULL; >> - return err; >> + ret = err; >> + goto err_put; >> } >> >> /* Register our halt function */ >> @@ -122,8 +128,12 @@ static int gpio_halt_probe(struct platform_device *pdev) >> >> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >> " irq).\n", gpio, trigger, irq); >> + ret = 0; >> + halt_node = of_node_get(child_node); > >LGTM, but my preferred style would be: > halt_node = child_node; > return 0; >I'm not a maintainer, so this is just my opinion and it is mostly a >mater of taste. > >CJ Thanks, CJ. Now, I also prefer this style and I will use it. > >> >> - return 0; >> +err_put: >> + of_node_put(child_node); >> + return ret; >> } >> >> static int gpio_halt_remove(struct platform_device *pdev) >> @@ -139,6 +149,7 @@ static int gpio_halt_remove(struct platform_device *pdev) >> >> gpio_free(gpio); >> >> + of_node_put(halt_node); >> halt_node = NULL; >> } >>