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(). 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 > >>>>>>> > >>>>>> > >>>>> > >>>> > >> >
