Re: [PATCH v2] gpiolib: Show correct direction from the beginning

[Jeffrey Hugo]

On 10/1/2018 7:36 AM, Ricardo Ribalda Delgado wrote:
> Hi Linus
> On Mon, Oct 1, 2018 at 1:54 PM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
> > On Fri, Sep 28, 2018 at 9:30 PM Ricardo Ribalda Delgado
> > <ricardo.ribalda@xxxxxxxxx> wrote:
> >
> > > How do we proceed from here? Can you fix your driver somehow to
> > > init the valid mask before enabling the gpio?
> >
> > Just include a hunk to the qcom driver reordering this call
> > at the same time. No need to make it separate patches,
> > it need to be tested together anyways.
> >
> > I guess just switch the order of these two:
> >
> >          ret = gpiochip_add_data(&pctrl->chip, pctrl);
> >          if (ret) {
> >                  dev_err(pctrl->dev, "Failed register gpiochip\n");
> >                  return ret;
> >          }
> >
> >          ret = msm_gpio_init_valid_mask(chip, pctrl);
> >          if (ret) {
> >                  dev_err(pctrl->dev, "Failed to setup irq valid bits\n");
> >                  gpiochip_remove(&pctrl->chip);
> >                  return ret;
> >          }
>
> the problem is that valid_mask is not a long/integer, is a struct that
> needs to be malloced, and is malloc at gpiochip_add_data :(
>
> Maybe we need a callback from the driver to init that mask just after
> the allocation?
>
> A fast grep shows that the only driver using need_valid_mask (not for
> irq) is msm:
>
> ricardo@neopili:~/curro/kernel-upstream$ git grep "need_valid_mask ="
> | grep -v irq
> drivers/gpio/gpiolib.c: gpiochip->need_valid_mask = true;
> drivers/pinctrl/intel/pinctrl-cherryview.c: bool need_valid_mask =
> !dmi_check_system(chv_no_valid_mask);
> drivers/pinctrl/qcom/pinctrl-msm.c: chip->need_valid_mask =
> msm_gpio_needs_valid_mask(pctrl);
>
> so hacking something in the driver might not be a terrible idea.

IMO, hack up the driver and I'll test it.  We can figure out what is 
needed to work, then determine what is the proper solution for that.

--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm 
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.