* [PATCH] acpi: allow usage of acpi_tad without PRW @ 2022-12-02 15:34 Bart Groeneveld | GPX Solutions B.V 2022-12-02 18:04 ` Rafael J. Wysocki 0 siblings, 1 reply; 3+ messages in thread From: Bart Groeneveld | GPX Solutions B.V @ 2022-12-02 15:34 UTC (permalink / raw) To: Rafael J. Wysocki, Len Brown, linux-acpi, linux-kernel Cc: Bart Groeneveld | GPX Solutions B.V. From: "Bart Groeneveld | GPX Solutions B.V." <bart@gpxbv.nl> Not all tads have the PRW capability, which is totally OK, according to the ACPI spec [1]: > _PRW is only required for devices that have the ability to wake > the system from a system sleeping state. This partially solves [2] and [3]. [1]: https://uefi.org/sites/default/files/resources/ACPI_Spec_6_4_Jan22.pdf [2]: https://bugzilla.kernel.org/show_bug.cgi?id=212313 [3]: https://github.com/linux-surface/linux-surface/issues/415 Signed-off-by: Bart Groeneveld | GPX Solutions B.V. <bart@gpxbv.nl> --- drivers/acpi/acpi_tad.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c index e9b8e8305e23..67f71fa4362f 100644 --- a/drivers/acpi/acpi_tad.c +++ b/drivers/acpi/acpi_tad.c @@ -604,11 +604,6 @@ static int acpi_tad_probe(struct platform_device *pdev) return -ENODEV; } - if (!acpi_has_method(handle, "_PRW")) { - dev_info(dev, "Missing _PRW\n"); - return -ENODEV; - } - dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL); if (!dd) return -ENOMEM; -- 2.38.1 ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] acpi: allow usage of acpi_tad without PRW 2022-12-02 15:34 [PATCH] acpi: allow usage of acpi_tad without PRW Bart Groeneveld | GPX Solutions B.V @ 2022-12-02 18:04 ` Rafael J. Wysocki 2022-12-05 15:08 ` [PATCH v2] acpi: allow usage of acpi_tad on HW-reduced platforms Bart Groeneveld | GPX Solutions B.V 0 siblings, 1 reply; 3+ messages in thread From: Rafael J. Wysocki @ 2022-12-02 18:04 UTC (permalink / raw) To: Bart Groeneveld | GPX Solutions B.V Cc: Rafael J. Wysocki, Len Brown, linux-acpi, linux-kernel On Fri, Dec 2, 2022 at 4:36 PM Bart Groeneveld | GPX Solutions B.V <bart@gpxbv.nl> wrote: > > From: "Bart Groeneveld | GPX Solutions B.V." <bart@gpxbv.nl> > > Not all tads have the PRW capability, which is totally OK, > according to the ACPI spec [1]: > > > _PRW is only required for devices that have the ability to wake > > the system from a system sleeping state. No, the ACPI TAD definition in Section 9.17 (ACPI 6.5) specifically requires _PRW to be present unless the system is hardware-reduced. Anyway, the RTC part can still be supported without _PRW, but then the wakeup-related attributes should not be present in such cases. > This partially solves [2] and [3]. > > [1]: https://uefi.org/sites/default/files/resources/ACPI_Spec_6_4_Jan22.pdf > [2]: https://bugzilla.kernel.org/show_bug.cgi?id=212313 > [3]: https://github.com/linux-surface/linux-surface/issues/415 > > Signed-off-by: Bart Groeneveld | GPX Solutions B.V. <bart@gpxbv.nl> > --- > drivers/acpi/acpi_tad.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c > index e9b8e8305e23..67f71fa4362f 100644 > --- a/drivers/acpi/acpi_tad.c > +++ b/drivers/acpi/acpi_tad.c > @@ -604,11 +604,6 @@ static int acpi_tad_probe(struct platform_device *pdev) > return -ENODEV; > } > > - if (!acpi_has_method(handle, "_PRW")) { > - dev_info(dev, "Missing _PRW\n"); > - return -ENODEV; > - } > - This may be sufficient for the RTC part alone to work, but making the wakeup-related attributes available doesn't really make sense in the _PRW absent case, so they all should be made optional. > dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL); > if (!dd) > return -ENOMEM; > -- ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v2] acpi: allow usage of acpi_tad on HW-reduced platforms 2022-12-02 18:04 ` Rafael J. Wysocki @ 2022-12-05 15:08 ` Bart Groeneveld | GPX Solutions B.V 0 siblings, 0 replies; 3+ messages in thread From: Bart Groeneveld | GPX Solutions B.V @ 2022-12-05 15:08 UTC (permalink / raw) To: Rafael J. Wysocki, Len Brown, linux-acpi, linux-kernel Cc: Bart Groeneveld | GPX Solutions B.V. From: "Bart Groeneveld | GPX Solutions B.V." <bart@gpxbv.nl> The specification [1] allows so-called HW-reduced platforms, which do not implement everything, especially the wakeup related stuff. In that case, it is still usable as a RTC. This is helpful for [2] and [3], which is about a device with no other working RTC, but it does have an HW-reduced TAD, which can be used as a RTC instead. [1]: https://uefi.org/specs/ACPI/6.5/09_ACPI_Defined_Devices_and_Device_Specific_Objects.html#time-and-alarm-device [2]: https://bugzilla.kernel.org/show_bug.cgi?id=212313 [3]: https://github.com/linux-surface/linux-surface/issues/415 Signed-off-by: Bart Groeneveld | GPX Solutions B.V. <bart@gpxbv.nl> --- drivers/acpi/acpi_tad.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c index e9b8e8305e23..944276934e7e 100644 --- a/drivers/acpi/acpi_tad.c +++ b/drivers/acpi/acpi_tad.c @@ -432,6 +432,14 @@ static ssize_t caps_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(caps); +static struct attribute *acpi_tad_attrs[] = { + &dev_attr_caps.attr, + NULL, +}; +static const struct attribute_group acpi_tad_attr_group = { + .attrs = acpi_tad_attrs, +}; + static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -480,15 +488,14 @@ static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RW(ac_status); -static struct attribute *acpi_tad_attrs[] = { - &dev_attr_caps.attr, +static struct attribute *acpi_tad_ac_attrs[] = { &dev_attr_ac_alarm.attr, &dev_attr_ac_policy.attr, &dev_attr_ac_status.attr, NULL, }; -static const struct attribute_group acpi_tad_attr_group = { - .attrs = acpi_tad_attrs, +static const struct attribute_group acpi_tad_ac_attr_group = { + .attrs = acpi_tad_ac_attrs, }; static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr, @@ -563,13 +570,18 @@ static int acpi_tad_remove(struct platform_device *pdev) pm_runtime_get_sync(dev); + if (dd->capabilities & ACPI_TAD_AC_WAKE) + sysfs_remove_group(&dev->kobj, &acpi_tad_ac_attr_group); + if (dd->capabilities & ACPI_TAD_DC_WAKE) sysfs_remove_group(&dev->kobj, &acpi_tad_dc_attr_group); sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group); - acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER); - acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER); + if (dd->capabilities & ACPI_TAD_AC_WAKE) { + acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER); + acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER); + } if (dd->capabilities & ACPI_TAD_DC_WAKE) { acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER); acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER); @@ -604,11 +616,6 @@ static int acpi_tad_probe(struct platform_device *pdev) return -ENODEV; } - if (!acpi_has_method(handle, "_PRW")) { - dev_info(dev, "Missing _PRW\n"); - return -ENODEV; - } - dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL); if (!dd) return -ENOMEM; @@ -637,6 +644,12 @@ static int acpi_tad_probe(struct platform_device *pdev) if (ret) goto fail; + if (caps & ACPI_TAD_AC_WAKE) { + ret = sysfs_create_group(&dev->kobj, &acpi_tad_ac_attr_group); + if (ret) + goto fail; + } + if (caps & ACPI_TAD_DC_WAKE) { ret = sysfs_create_group(&dev->kobj, &acpi_tad_dc_attr_group); if (ret) -- 2.38.1 ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-12-05 15:09 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-12-02 15:34 [PATCH] acpi: allow usage of acpi_tad without PRW Bart Groeneveld | GPX Solutions B.V 2022-12-02 18:04 ` Rafael J. Wysocki 2022-12-05 15:08 ` [PATCH v2] acpi: allow usage of acpi_tad on HW-reduced platforms Bart Groeneveld | GPX Solutions B.V
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