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> -----Original Message-----
> From: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> Sent: Thursday, March 17, 2022 11:46
> To: Limonciello, Mario <Mario.Limonciello@xxxxxxx>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>; Mark Gross
> <mgross@xxxxxxxxxxxxxxx>; Rafael J . Wysocki <rjw@xxxxxxxxxxxxx>; open
> list:X86 PLATFORM DRIVERS <platform-driver-x86@xxxxxxxxxxxxxxx>; ACPI
> Devel Maling List <linux-acpi@xxxxxxxxxxxxxxx>; S-k, Shyam-sundar <Shyam-
> sundar.S-k@xxxxxxx>; Goswami, Sanket <Sanket.Goswami@xxxxxxx>
> Subject: Re: [PATCH v5 1/4] ACPI / x86: Add support for LPS0 callback handler
>
> On Thu, Mar 17, 2022 at 3:15 PM Mario Limonciello
> <mario.limonciello@xxxxxxx> wrote:
> >
> > Currenty the latest thing run during a suspend to idle attempt is
> > the LPS0 `prepare_late` callback and the earliest thing is the
> > `resume_early` callback.
> >
> > There is a desire for the `amd-pmc` driver to suspend later in the
> > suspend process (ideally the very last thing), so create a callback
> > that it or any other driver can hook into to do this.
> >
> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
>
> This looks good to me, so:
>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
Thanks!
> and I don't have any conflicting changes queued up for 5.17, so from
> my POV it can go in via the x86 platform drivers tree along with the
> other patches in the series.
Hans,
FYI the series is based off of platform-x86/for-next also with changes to amd-pmc
Rafael doesn't have in his tree, so I also agree it's better to go through x86 platform
drivers.
>
> > ---
> > changes from v4->v5:
> > * fix a check for handler->prepare
> > Reported by Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > changes from v3->v4:
> > * drop use of mutex, use lock_system_sleep instead
> > * don't pass argument of context, driver will maintain this internally
> > * don't allow failing prepare stage
> > * don't allow unregistering if sleep_no_lps0 is set
> > changes from v2->v3:
> > * Check that callbacks exist before calling
> > changes from v1->v2:
> > * Change register/unregister arguments to be struct
> >
> > drivers/acpi/x86/s2idle.c | 40
> +++++++++++++++++++++++++++++++++++++++
> > include/linux/acpi.h | 10 +++++++++-
> > 2 files changed, 49 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
> > index abc06e7f89d8..031b20a547f9 100644
> > --- a/drivers/acpi/x86/s2idle.c
> > +++ b/drivers/acpi/x86/s2idle.c
> > @@ -86,6 +86,8 @@ struct lpi_device_constraint_amd {
> > int min_dstate;
> > };
> >
> > +static LIST_HEAD(lps0_s2idle_devops_head);
> > +
> > static struct lpi_constraints *lpi_constraints_table;
> > static int lpi_constraints_table_size;
> > static int rev_id;
> > @@ -444,6 +446,8 @@ static struct acpi_scan_handler lps0_handler = {
> >
> > int acpi_s2idle_prepare_late(void)
> > {
> > + struct acpi_s2idle_dev_ops *handler;
> > +
> > if (!lps0_device_handle || sleep_no_lps0)
> > return 0;
> >
> > @@ -474,14 +478,26 @@ int acpi_s2idle_prepare_late(void)
> > acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
> > lps0_dsm_func_mask_microsoft,
> lps0_dsm_guid_microsoft);
> > }
> > +
> > + list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
> > + if (handler->prepare)
> > + handler->prepare();
> > + }
> > +
> > return 0;
> > }
> >
> > void acpi_s2idle_restore_early(void)
> > {
> > + struct acpi_s2idle_dev_ops *handler;
> > +
> > if (!lps0_device_handle || sleep_no_lps0)
> > return;
> >
> > + list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
> > + if (handler->restore)
> > + handler->restore();
> > +
> > /* Modern standby exit */
> > if (lps0_dsm_func_mask_microsoft > 0)
> > acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
> > @@ -524,4 +540,28 @@ void acpi_s2idle_setup(void)
> > s2idle_set_ops(&acpi_s2idle_ops_lps0);
> > }
> >
> > +int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
> > +{
> > + if (!lps0_device_handle || sleep_no_lps0)
> > + return -ENODEV;
> > +
> > + lock_system_sleep();
> > + list_add(&arg->list_node, &lps0_s2idle_devops_head);
> > + unlock_system_sleep();
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);
> > +
> > +void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg)
> > +{
> > + if (!lps0_device_handle || sleep_no_lps0)
> > + return;
> > +
> > + lock_system_sleep();
> > + list_del(&arg->list_node);
> > + unlock_system_sleep();
> > +}
> > +EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);
> > +
> > #endif /* CONFIG_SUSPEND */
> > diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> > index 6274758648e3..47c16cdc8e0e 100644
> > --- a/include/linux/acpi.h
> > +++ b/include/linux/acpi.h
> > @@ -1023,7 +1023,15 @@ void acpi_os_set_prepare_extended_sleep(int
> (*func)(u8 sleep_state,
> >
> > acpi_status acpi_os_prepare_extended_sleep(u8 sleep_state,
> > u32 val_a, u32 val_b);
> > -
> > +#ifdef CONFIG_X86
> > +struct acpi_s2idle_dev_ops {
> > + struct list_head list_node;
> > + void (*prepare)(void);
> > + void (*restore)(void);
> > +};
> > +int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg);
> > +void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg);
> > +#endif /* CONFIG_X86 */
> > #ifndef CONFIG_IA64
> > void arch_reserve_mem_area(acpi_physical_address addr, size_t size);
> > #else
> > --
> > 2.34.1
> >
