Re: [PATCH v4 1/2] gpio: gpiolib: Generalise state persistence beyond sleep
From: Linus Walleij <hidden>
Date: 2017-12-02 15:20:41
Also in:
linux-aspeed, linux-gpio, lkml, openbmc
On Thu, Nov 30, 2017 at 4:55 AM, Andrew Jeffery [off-list ref] 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 <redacted> Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com> Acked-by: Rob Herring <robh@kernel.org>
Nice work, patch applied!
quoted hunk ↗ jump to hunk
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