Messages in this thread | | | From | Linus Walleij <> | Date | Sat, 2 Dec 2017 16:20:37 +0100 | Subject | Re: [PATCH v4 1/2] gpio: gpiolib: Generalise state persistence beyond sleep |
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On Thu, Nov 30, 2017 at 4:55 AM, Andrew Jeffery <andrew@aj.id.au> wrote:
> General support for state persistence is added to gpiolib with the > introduction of a new pinconf parameter to propagate the request to > hardware. The existing persistence support for sleep is adapted to > include hardware support if the GPIO driver provides it. Persistence > continues to be enabled by default; in-kernel consumers can opt out, but > userspace (currently) does not have a choice. > > The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are > renamed, dropping the SLEEP prefix to reflect that the concept is no > longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE > could initially be misinterpreted, so I've further changed the symbols > to *_TRANSITORY and *_PERSISTENT to address this. > > The sysfs interface is modified only to keep consistency with the > chardev interface in enforcing persistence for userspace exports. > > Signed-off-by: Andrew Jeffery <andrew@aj.id.au> > Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com> > Acked-by: Rob Herring <robh@kernel.org>
Nice work, patch applied!
> diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c > index 3f454eaf2101..0bd472ffb072 100644 > --- a/drivers/gpio/gpiolib-sysfs.c > +++ b/drivers/gpio/gpiolib-sysfs.c > @@ -474,11 +474,15 @@ static ssize_t export_store(struct class *class, > status = -ENODEV; > goto done; > } > - status = gpiod_export(desc, true); > - if (status < 0) > - gpiod_free(desc); > - else > - set_bit(FLAG_SYSFS, &desc->flags); > + > + status = gpiod_set_transitory(desc, false); > + if (!status) { > + status = gpiod_export(desc, true); > + if (status < 0) > + gpiod_free(desc); > + else > + set_bit(FLAG_SYSFS, &desc->flags); > + }
Part of me just wanna drop this hunk of the patch and let the old sysfs ABI rot.
But I guess that is especially malevolent so I will abstain.
Yours, Linus Walleij
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