On 10/8/23 11:48 PM, Bartosz Golaszewski wrote: > On Thu, Oct 5, 2023 at 9:43 PM Dipen Patel <dipenp@xxxxxxxxxx> wrote: >> >> On 10/5/23 12:05 PM, Bartosz Golaszewski wrote: >>> On Thu, Oct 5, 2023 at 8:12 PM Dipen Patel <dipenp@xxxxxxxxxx> wrote: >>>> >>>> On 10/5/23 6:48 AM, Bartosz Golaszewski wrote: >>>>> On Thu, Oct 5, 2023 at 1:52 AM Dipen Patel <dipenp@xxxxxxxxxx> wrote: >>>>>> >>>>>> On 10/4/23 3:54 PM, Dipen Patel wrote: >>>>>>> On 10/4/23 1:33 PM, Dipen Patel wrote: >>>>>>>> On 10/4/23 1:30 PM, Dipen Patel wrote: >>>>>>>>> On 10/4/23 5:00 AM, Bartosz Golaszewski wrote: >>>>>>>>>> On Thu, Sep 7, 2023 at 9:28 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: >>>>>>>>>>> >>>>>>>>>>> On Tue, Sep 5, 2023 at 8:53 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote: >>>>>>>>>>> >>>>>>>>>>>> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> >>>>>>>>>>>> >>>>>>>>>>>> Using struct gpio_chip is not safe as it will disappear if the >>>>>>>>>>>> underlying driver is unbound for any reason. Switch to using reference >>>>>>>>>>>> counted struct gpio_device and its dedicated accessors. >>>>>>>>>>>> >>>>>>>>>>>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> >>>>>>>>>>> >>>>>>>>>>> As Andy points out add <linux/cleanup.h>, with that fixed: >>>>>>>>>>> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> >>>>>>>>>>> >>>>>>>>>>> I think this can be merged into the gpio tree after leaving some >>>>>>>>>>> slack for the HTE maintainer to look at it, things look so much >>>>>>>>>>> better after this. >>>>>>>>>>> >>>>>>>>>>> Yours, >>>>>>>>>>> Linus Walleij >>>>>>>>>> >>>>>>>>>> Dipen, >>>>>>>>>> >>>>>>>>>> if you could give this patch a test and possibly ack it for me to take >>>>>>>>>> it through the GPIO tree (or go the immutable tag from HTE route) then >>>>>>>>>> it would be great. This is the last user of gpiochip_find() treewide, >>>>>>>>>> so with it we could remove it entirely for v6.7. >>>>>>>>> >>>>>>>>> Progress so far for the RFT... >>>>>>>>> >>>>>>>>> I tried applying the patch series on 6.6-rc1 and it did not apply cleanly, >>>>>>>>> some patches I needed to manually apply and correct. With all this, it failed >>>>>>>>> compilation at some spi/spi-bcm2835 driver. I disabled that and was able to >>>>>>>>> compile. I thought I should let you know this part. >>>>>>>>> >>>>>>>>> Now, I tried to test the hte and it seems to fail finding the gpio device, >>>>>>>>> roughly around this place [1]. I thought it would be your patch series so >>>>>>>>> tried to just use 6.6rc1 without your patches and it still failed at the >>>>>>>>> same place. I have to trace back now from which kernel version it broke. >>>>>>>> >>>>>>>> [1]. >>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/pateldipen1984/linux.git/tree/drivers/hte/hte-tegra194.c?h=for-next#n781 >>>>>>>> >>>>>>>> of course with your patches it would fail for the gdev instead of the chip. >>>>>>> >>>>>>> Small update: >>>>>>> >>>>>>> I put some debugging prints in the gpio match function in the hte-tegra194.c as >>>>>>> below: >>>>>>> >>>>>>> static int tegra_gpiochip_match(struct gpio_chip *chip, void *data) >>>>>>> { >>>>>>> + struct device_node *node = data; >>>>>>> + struct fwnode_handle *fw = of_node_to_fwnode(data); >>>>>>> + if (!fw || !chip->fwnode) >>>>>>> + pr_err("dipen patel: fw is null\n"); >>>>>>> >>>>>>> - pr_err("%s:%d\n", __func__, __LINE__); >>>>>>> + pr_err("dipen patel, %s:%d: %s, %s, %s, match?:%d, fwnode name:%s\n", >>>>>>> __func__, __LINE__, chip->label, node->name, node->full_name, (chip->fwnode == >>>>>>> fw), fw->dev->init_name); >>>>>>> return chip->fwnode == of_node_to_fwnode(data); >>>>>>> } >>>>>>> >>>>>>> The output of the printfs looks like below: >>>>>>> [ 3.955194] dipen patel: fw is null -----> this message started appearing >>>>>>> when I added !chip->fwnode test in the if condition line. >>>>>>> >>>>>>> [ 3.958864] dipen patel, tegra_gpiochip_match:689: tegra234-gpio, gpio, >>>>>>> gpio@c2f0000, match?:0, fwnode name:(null) >>>>>>> >>>>>>> I conclude that chip->fwnode is empty. Any idea in which conditions that node >>>>>>> would be empty? >>>>>> >>>>>> sorry for spamming, one last message before I sign off for the day.... >>>>>> >>>>>> Seems, adding below in the tegra gpio driver resolved the issue I am facing, I >>>>>> was able to verify your patch series. >>>>>> >>>>>> diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c >>>>>> index d87dd06db40d..a56c159d7136 100644 >>>>>> --- a/drivers/gpio/gpio-tegra186.c >>>>>> +++ b/drivers/gpio/gpio-tegra186.c >>>>>> @@ -989,6 +989,8 @@ static int tegra186_gpio_probe(struct platform_device *pdev) >>>>>> offset += port->pins; >>>>>> } >>>>>> >>>>>> + gpio->gpio.fwnode = of_node_to_fwnode(pdev->dev.of_node); >>>>>> + >>>>>> return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio, gpio); >>>>>> } >>>>>> >>>>>> Now, few follow up questions: >>>>>> 1) is this the correct way of setting the chip fwnode in the gpio driver? >>>>> >>>>> You shouldn't need this. This driver already does: >>>>> >>>>> gpio->gpio.parent = &pdev->dev; >>>>> >>>>> so fwnode should be assigned in gpiochip_add_data_with_key(). Can you >>>>> check why this doesn't happen? >>>> >>>> I do not see anywhere chip->fwnode being set in the gpiochip_add_* function. >>>> The only reference I see is here [1]. Does it mean I need to change my match >>>> function from: >>>> >>>> chip->fwnode == of_node_to_fwnode(data) >>>> >>>> to: >>>> dev_fwnode(chip->parent) == of_node_to_fwnode(data)? >>> >>> No! chip->fwnode is only used to let GPIOLIB know which fwnode to >>> assign to the GPIO device (struct gpio_device). >> What do you suggest I should use for the match as I do not see chip->fwnode >> being set? >> > > This is most likely going to be a longer discussion. I suggest that in > the meantime you just assign the gc->fwnode pointer explicitly from > the platform device in the tegra GPIO driver and use it in the lookup > function. Note that this is NOT wrong or a hack. It's just that most > devices don't need to be looked up using gpio_device_find(). Sure, at the same time, I am also find to use any other method/s. > > Bart > >>> >>> Bart >>> >>>> >>>> [1]: >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpio/gpiolib.c?h=v6.6-rc1#n767 >>>> >>>>> >>>>> Bart >>>>> >>>>>> 2) Or should I use something else in hte matching function instead of fwnode so >>>>>> to avoid adding above line in the gpio driver? >>>>>> >>>>>>> >>>>>>>>> >>>>>>>>>> >>>>>>>>>> Bart >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>> >>
