2021-09-07 00:45:00

by Dimitri John Ledkov

Subject: [PATCH] riscv: set default pm_power_off to NULL

Set pm_power_off to NULL like on all other architectures, check if it
is set in machine_halt() and machine_power_off() and fallback to
default_power_off if no other power driver got registered.

This brings riscv architecture inline with all other architectures,
and allows to reuse exiting power drivers unmodified.

Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
not set), do not set pm_power_off to sbi_shutdown(). There is no
support for SBI v0.3 system reset extension either. This prevents
using gpio_poweroff on SiFive HiFive Unmatched.

Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
node and kernel complied without CONFIG_RISCV_SBI_V01.

BugLink: https://bugs.launchpad.net/bugs/1942806
Signed-off-by: Dimitri John Ledkov <[email protected]>
---
arch/riscv/kernel/reset.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
index ee5878d968..9c842c4168 100644
--- a/arch/riscv/kernel/reset.c
+++ b/arch/riscv/kernel/reset.c
@@ -12,7 +12,7 @@ static void default_power_off(void)
wait_for_interrupt();
}

-void (*pm_power_off)(void) = default_power_off;
+void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);

void machine_restart(char *cmd)
@@ -23,10 +23,16 @@ void machine_restart(char *cmd)

void machine_halt(void)
{
- pm_power_off();
+ if (pm_power_off != NULL)
+ pm_power_off();
+ else
+ default_power_off();
}

void machine_power_off(void)
{
- pm_power_off();
+ if (pm_power_off != NULL)
+ pm_power_off();
+ else
+ default_power_off();
}
--
2.30.2

2021-09-07 04:06:09

by Anup Patel

Subject: Re: [PATCH] riscv: set default pm_power_off to NULL

On Tue, Sep 7, 2021 at 5:59 AM Dimitri John Ledkov
<[email protected]> wrote:
>
> Set pm_power_off to NULL like on all other architectures, check if it
> is set in machine_halt() and machine_power_off() and fallback to
> default_power_off if no other power driver got registered.
>
> This brings riscv architecture inline with all other architectures,
> and allows to reuse exiting power drivers unmodified.
>
> Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
> not set), do not set pm_power_off to sbi_shutdown(). There is no
> support for SBI v0.3 system reset extension either. This prevents
> using gpio_poweroff on SiFive HiFive Unmatched.
>
> Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
> node and kernel complied without CONFIG_RISCV_SBI_V01.
>
> BugLink: https://bugs.launchpad.net/bugs/1942806
> Signed-off-by: Dimitri John Ledkov <[email protected]>

Looks good to me.

Reviewed-by: Anup Patel <[email protected]>

BTW, SBI v0.3 system reset patch can be merged any day
because SBI v0.3 spec is already released.

Regards,
Anup

> ---
> arch/riscv/kernel/reset.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
> index ee5878d968..9c842c4168 100644
> --- a/arch/riscv/kernel/reset.c
> +++ b/arch/riscv/kernel/reset.c
> @@ -12,7 +12,7 @@ static void default_power_off(void)
> wait_for_interrupt();
> }
>
> -void (*pm_power_off)(void) = default_power_off;
> +void (*pm_power_off)(void) = NULL;
> EXPORT_SYMBOL(pm_power_off);
>
> void machine_restart(char *cmd)
> @@ -23,10 +23,16 @@ void machine_restart(char *cmd)
>
> void machine_halt(void)
> {
> - pm_power_off();
> + if (pm_power_off != NULL)
> + pm_power_off();
> + else
> + default_power_off();
> }
>
> void machine_power_off(void)
> {
> - pm_power_off();
> + if (pm_power_off != NULL)
> + pm_power_off();
> + else
> + default_power_off();
> }
> --
> 2.30.2
>

2021-09-09 06:36:29

by Ron Economos

Subject: Re: [PATCH] riscv: set default pm_power_off to NULL

On 9/6/21 5:28 PM, Dimitri John Ledkov wrote:

> Set pm_power_off to NULL like on all other architectures, check if it
> is set in machine_halt() and machine_power_off() and fallback to
> default_power_off if no other power driver got registered.
>
> This brings riscv architecture inline with all other architectures,
> and allows to reuse exiting power drivers unmodified.
>
> Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
> not set), do not set pm_power_off to sbi_shutdown(). There is no
> support for SBI v0.3 system reset extension either. This prevents
> using gpio_poweroff on SiFive HiFive Unmatched.
>
> Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
> node and kernel complied without CONFIG_RISCV_SBI_V01.
>
> BugLink: https://bugs.launchpad.net/bugs/1942806
> Signed-off-by: Dimitri John Ledkov <[email protected]>
> ---
> arch/riscv/kernel/reset.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
> index ee5878d968..9c842c4168 100644
> --- a/arch/riscv/kernel/reset.c
> +++ b/arch/riscv/kernel/reset.c
> @@ -12,7 +12,7 @@ static void default_power_off(void)
> wait_for_interrupt();
> }
>
> -void (*pm_power_off)(void) = default_power_off;
> +void (*pm_power_off)(void) = NULL;
> EXPORT_SYMBOL(pm_power_off);
>
> void machine_restart(char *cmd)
> @@ -23,10 +23,16 @@ void machine_restart(char *cmd)
>
> void machine_halt(void)
> {
> - pm_power_off();
> + if (pm_power_off != NULL)
> + pm_power_off();
> + else
> + default_power_off();
> }
>
> void machine_power_off(void)
> {
> - pm_power_off();
> + if (pm_power_off != NULL)
> + pm_power_off();
> + else
> + default_power_off();
> }

Works good here. Tested on HiFive Unmatched, Ubuntu 21.04 and kernel 5.14.2

Tested-by: Ron Economos <[email protected]>

2021-10-03 17:12:01

by Palmer Dabbelt

Subject: Re: [PATCH] riscv: set default pm_power_off to NULL

On Mon, 06 Sep 2021 17:28:47 PDT (-0700), [email protected] wrote:
> Set pm_power_off to NULL like on all other architectures, check if it
> is set in machine_halt() and machine_power_off() and fallback to
> default_power_off if no other power driver got registered.
>
> This brings riscv architecture inline with all other architectures,
> and allows to reuse exiting power drivers unmodified.
>
> Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
> not set), do not set pm_power_off to sbi_shutdown(). There is no
> support for SBI v0.3 system reset extension either. This prevents
> using gpio_poweroff on SiFive HiFive Unmatched.
>
> Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
> node and kernel complied without CONFIG_RISCV_SBI_V01.
>
> BugLink: https://bugs.launchpad.net/bugs/1942806
> Signed-off-by: Dimitri John Ledkov <[email protected]>
> ---
> arch/riscv/kernel/reset.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
> index ee5878d968..9c842c4168 100644
> --- a/arch/riscv/kernel/reset.c
> +++ b/arch/riscv/kernel/reset.c
> @@ -12,7 +12,7 @@ static void default_power_off(void)
> wait_for_interrupt();
> }
>
> -void (*pm_power_off)(void) = default_power_off;
> +void (*pm_power_off)(void) = NULL;
> EXPORT_SYMBOL(pm_power_off);
>
> void machine_restart(char *cmd)
> @@ -23,10 +23,16 @@ void machine_restart(char *cmd)
>
> void machine_halt(void)
> {
> - pm_power_off();
> + if (pm_power_off != NULL)
> + pm_power_off();
> + else
> + default_power_off();
> }
>
> void machine_power_off(void)
> {
> - pm_power_off();
> + if (pm_power_off != NULL)
> + pm_power_off();
> + else
> + default_power_off();
> }

Thanks, this is on for-next.