[PATCH v3 0/6] reset: add board reset type

[PATCH v3 0/6] reset: add board reset type

[dmukhin]

This series introduces convenience functionality for prototype boards
where reset is not fully working - for example, where only warm reset is
functional, but cold reset must still be enabled for the production
variant.

Patch 1 allows per-board default reset override.
Patch 2 adds `reset -c` support to explicitly trigger cold reset.
Patch 3 adds reset type printout on the console.
Patch 4 introduces a small fixup for the x86 reset driver.
Patch 5 updates documentation for reset command.
Patch 6 updates reset command tests.

Denis Mukhin (6):
  reset: Allow per-board reset type
  reset: Add explicit cold reset support
  reset: Print reset type on diagnostic console
  reset: x86: Use cpu_hlt() in pch_sysreset_power_off()
  docs: reset: document cold reset option
  tests: reset: add cold/warm reset types

 cmd/boot.c                         |  3 +-
 doc/usage/cmd/reset.rst            |  8 +++++
 drivers/sysreset/Kconfig           | 31 ++++++++++++++++++
 drivers/sysreset/sysreset-uclass.c | 50 +++++++++++++++++++++++++++---
 drivers/sysreset/sysreset_x86.c    |  5 +--
 test/py/tests/test_reset.py        |  8 ++---
 6 files changed, 94 insertions(+), 11 deletions(-)

-- 
2.54.0

[PATCH v3 1/6] reset: Allow per-board reset type

[dmukhin]

From: Denis Mukhin <dmukhin@ford.com> 

Some prototype boards may not have (temporarily) all required reset
types supported (e.g. only warm reset supported).

Add a Kconfig choice to select the board-specific default reset type
used by the `reset` command, allowing it to work on such boards.

Keep cold reset as the default.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v2:
- n/a
---
 drivers/sysreset/Kconfig           | 31 ++++++++++++++++++++++++++++++
 drivers/sysreset/sysreset-uclass.c | 19 +++++++++++++++++-
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 90f740f51d42..2584c2b203e5 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -57,6 +57,37 @@ config SYSRESET_CMD_RESET_ARGS
 	  additional arguments for implementing arch/board specific
 	  functionality.
 
+if SYSRESET_CMD_RESET
+choice
+	prompt "Default reset type for reset command"
+	default SYSRESET_CMD_RESET_DEFAULT_COLD
+	help
+	  Select the default reset type used by the reset command when no
+	  explicit reset type is requested.
+
+config SYSRESET_CMD_RESET_DEFAULT_WARM
+	bool "Warm reset"
+	help
+	  Reset CPU while keeping GPIOs active.
+
+config SYSRESET_CMD_RESET_DEFAULT_COLD
+	bool "Cold reset"
+	help
+	  Reset CPU and GPIOs.
+
+config SYSRESET_CMD_RESET_DEFAULT_POWER
+	bool "Power reset"
+	help
+	  Reset PMIC by removing and restoring power.
+
+config SYSRESET_CMD_RESET_DEFAULT_POWER_OFF
+	bool "Power off"
+	help
+	  Turn off power.
+
+endchoice
+endif
+
 if CMD_POWEROFF
 
 config SYSRESET_CMD_POWEROFF
diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
index f25e09e9cd06..d2fddb470bf1 100644
--- a/drivers/sysreset/sysreset-uclass.c
+++ b/drivers/sysreset/sysreset-uclass.c
@@ -150,9 +150,26 @@ void reset_cpu(void)
 }
 
 #if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET)
+static enum sysreset_t sysreset_get_default_type(void)
+{
+	if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_WARM))
+		return SYSRESET_WARM;
+
+	if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_COLD))
+		return SYSRESET_COLD;
+
+	if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_POWER))
+		return SYSRESET_POWER;
+
+	if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_POWER_OFF))
+		return SYSRESET_POWER_OFF;
+
+	return SYSRESET_COLD;
+}
+
 int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
-	enum sysreset_t reset_type = SYSRESET_COLD;
+	enum sysreset_t reset_type = sysreset_get_default_type();
 
 	if (argc > 2)
 		return CMD_RET_USAGE;
-- 
2.54.0

Re: [PATCH v3 1/6] reset: Allow per-board reset type

[Simon Glass]

Hi Denis,

On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> reset: Allow per-board reset type
>
> Some prototype boards may not have (temporarily) all required reset
> types supported (e.g. only warm reset supported).
>
> Add a Kconfig choice to select the board-specific default reset type
> used by the reset command, allowing it to work on such boards.
>
> Keep cold reset as the default.
>
> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
>
> drivers/sysreset/Kconfig           | 31 +++++++++++++++++++++++++++++++
>  drivers/sysreset/sysreset-uclass.c | 19 ++++++++++++++++++-
>  2 files changed, 49 insertions(+), 1 deletion(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

> diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
> @@ -57,6 +57,37 @@ config SYSRESET_CMD_RESET_ARGS
> +config SYSRESET_CMD_RESET_DEFAULT_WARM
> +     bool "Warm reset"
> +     help
> +       Reset CPU while keeping GPIOs active.
> +
> +config SYSRESET_CMD_RESET_DEFAULT_COLD
> +     bool "Cold reset"
> +     help
> +       Reset CPU and GPIOs.

This is very thin - as is the comment in include/sysreset.h - how about:

"Full cold reset of the machine, including CPU, GPIOs, PMIC and other
logic in the machine"

> diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
> @@ -57,6 +57,37 @@ config SYSRESET_CMD_RESET_ARGS
> +config SYSRESET_CMD_RESET_DEFAULT_POWER
> +     bool "Power reset"
> +     help
> +       Reset PMIC by removing and restoring power.
> +
> +config SYSRESET_CMD_RESET_DEFAULT_POWER_OFF
> +     bool "Power off"
> +     help
> +       Turn off power.

Could we use the 'poweroff' command instead?

> diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
> @@ -150,9 +150,26 @@ void reset_cpu(void)
> +static enum sysreset_t sysreset_get_default_type(void)
> +{
> +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_WARM))
> +             return SYSRESET_WARM;
> +
> +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_COLD))
> +             return SYSRESET_COLD;
> +
> +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_POWER))
> +             return SYSRESET_POWER;
> +
> +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_POWER_OFF))
> +             return SYSRESET_POWER_OFF;
> +
> +     return SYSRESET_COLD;
> +}

The trailing return SYSRESET_COLD is unreachable, BTW.

Regards,
Simon

Re: [PATCH v3 1/6] reset: Allow per-board reset type

[dmukhin]

On Mon, Jun 01, 2026 at 08:54:18AM -0600, Simon Glass wrote:
> Hi Denis,
> 
> On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> > reset: Allow per-board reset type
> >
> > Some prototype boards may not have (temporarily) all required reset
> > types supported (e.g. only warm reset supported).
> >
> > Add a Kconfig choice to select the board-specific default reset type
> > used by the reset command, allowing it to work on such boards.
> >
> > Keep cold reset as the default.
> >
> > Signed-off-by: Denis Mukhin <dmukhin@ford.com>
> >
> > drivers/sysreset/Kconfig           | 31 +++++++++++++++++++++++++++++++
> >  drivers/sysreset/sysreset-uclass.c | 19 ++++++++++++++++++-
> >  2 files changed, 49 insertions(+), 1 deletion(-)
> 
> Reviewed-by: Simon Glass <sjg@chromium.org>

Thanks!

> 
> > diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
> > @@ -57,6 +57,37 @@ config SYSRESET_CMD_RESET_ARGS
> > +config SYSRESET_CMD_RESET_DEFAULT_WARM
> > +     bool "Warm reset"
> > +     help
> > +       Reset CPU while keeping GPIOs active.
> > +
> > +config SYSRESET_CMD_RESET_DEFAULT_COLD
> > +     bool "Cold reset"
> > +     help
> > +       Reset CPU and GPIOs.
> 
> This is very thin - as is the comment in include/sysreset.h - how about:
> 
> "Full cold reset of the machine, including CPU, GPIOs, PMIC and other
> logic in the machine"
> 
> > diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
> > @@ -57,6 +57,37 @@ config SYSRESET_CMD_RESET_ARGS
> > +config SYSRESET_CMD_RESET_DEFAULT_POWER
> > +     bool "Power reset"
> > +     help
> > +       Reset PMIC by removing and restoring power.
> > +
> > +config SYSRESET_CMD_RESET_DEFAULT_POWER_OFF
> > +     bool "Power off"
> > +     help
> > +       Turn off power.
> 
> Could we use the 'poweroff' command instead?

Will drop SYSRESET_CMD_RESET_DEFAULT_POWER_OFF in v4 and leave
a code commentary to rely on poweroff command.

> 
> > diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
> > @@ -150,9 +150,26 @@ void reset_cpu(void)
> > +static enum sysreset_t sysreset_get_default_type(void)
> > +{
> > +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_WARM))
> > +             return SYSRESET_WARM;
> > +
> > +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_COLD))
> > +             return SYSRESET_COLD;
> > +
> > +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_POWER))
> > +             return SYSRESET_POWER;
> > +
> > +     if (IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_DEFAULT_POWER_OFF))
> > +             return SYSRESET_POWER_OFF;
> > +
> > +     return SYSRESET_COLD;
> > +}
> 
> The trailing return SYSRESET_COLD is unreachable, BTW.

Thanks for the catch!

> 
> Regards,
> Simon

[PATCH v3 2/6] reset: Add explicit cold reset support

[dmukhin]

From: Denis Mukhin <dmukhin@ford.com> 

Some prototype boards default to a non-cold reset type, e.g. warm reset.

Add `reset -c` so users can excplicitly request a cold reset when needed.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v2:
- n/a

Changes since v1:
- corrected args parsing in do_reset()
- updated commit message
- fixup reset command description
---
 cmd/boot.c                         |  3 ++-
 drivers/sysreset/sysreset-uclass.c | 13 +++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/cmd/boot.c b/cmd/boot.c
index 29cdf4a9a81a..2cef907e291e 100644
--- a/cmd/boot.c
+++ b/cmd/boot.c
@@ -59,13 +59,14 @@ U_BOOT_CMD(
 U_BOOT_CMD(
 	reset, 2, 0,	do_reset,
 	"Perform RESET of the CPU",
-	"- cold boot without level specifier\n"
+	"- reset without level specifier\n"
 #if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_ARGS)
 // All options handled by sysreset drivers via their sysreset_ops.request_arg callback
 #ifdef CONFIG_SYSRESET_QCOM_PSCI
 	"reset -edl - Boot to Emergency DownLoad mode\n"
 #endif
 #endif
+	"reset -c - cold reset if implemented\n"
 	"reset -w - warm reset if implemented"
 );
 
diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
index d2fddb470bf1..df68b5c3f9eb 100644
--- a/drivers/sysreset/sysreset-uclass.c
+++ b/drivers/sysreset/sysreset-uclass.c
@@ -174,8 +174,17 @@ int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	if (argc > 2)
 		return CMD_RET_USAGE;
 
-	if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'w') {
-		reset_type = SYSRESET_WARM;
+	if (argc == 2 && argv[1][0] == '-') {
+		switch (argv[1][1]) {
+		case 'c':
+			reset_type = SYSRESET_COLD;
+			break;
+		case 'w':
+			reset_type = SYSRESET_WARM;
+			break;
+		default:
+			return CMD_RET_USAGE;
+		}
 	}
 
 	printf("resetting ...\n");
-- 
2.54.0

Re: [PATCH v3 2/6] reset: Add explicit cold reset support

[Simon Glass]

Hi Denis,

On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> reset: Add explicit cold reset support
>
> Some prototype boards default to a non-cold reset type, e.g. warm reset.
>
> Add reset -c so users can excplicitly request a cold reset when needed.
>
> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
>
> cmd/boot.c                         |  3 ++-
>  drivers/sysreset/sysreset-uclass.c | 13 +++++++++++--
>  2 files changed, 13 insertions(+), 3 deletions(-)

> diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
> @@ -174,8 +174,17 @@ int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
>       if (argc > 2)
>               return CMD_RET_USAGE;
>
> -     if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'w') {
> -             reset_type = SYSRESET_WARM;
> +     if (argc == 2 && argv[1][0] == '-') {
> +             switch (argv[1][1]) {
> +             case 'c':
> +                     reset_type = SYSRESET_COLD;
> +                     break;
> +             case 'w':
> +                     reset_type = SYSRESET_WARM;
> +                     break;
> +             default:
> +                     return CMD_RET_USAGE;
> +             }
>       }

This regresses reset -edl on Qualcomm. Previously, an unknown -x
argument fell through to the SYSRESET_CMD_RESET_ARGS path, where
qcom_psci_sysreset_request_arg() picks up -edl and returns
-EINPROGRESS. With this change, argv[1][1] == 'e' hits the default
branch and bails out with CMD_RET_USAGE before sysreset_walk_arg()
runs, so reset -edl no longer works.

Please leave reset_type at its default for unrecognised flags (so the
arg-dispatch path can still claim them), or call sysreset_walk_arg()
first and only complain if nothing handled the argument. Also,
matching only argv[1][1] means reset -cx silently behaves like reset
-c - please tighten with strcmp() or a length check.

The could be a good usage for getopt() but sadly it increases code
size too much [1]

BTW -edl doesn't follow the normal flags approach, so we should
probably change that at some point.

> diff --git a/cmd/boot.c b/cmd/boot.c
> @@ -59,10 +59,11 @@ U_BOOT_CMD(
>  U_BOOT_CMD(
>       reset, 2, 0,    do_reset,
>       "Perform RESET of the CPU",
> -     "- cold boot without level specifier\n"
> +     "- reset without level specifier\n"
>  #ifdef CONFIG_SYSRESET_QCOM_PSCI
>       "reset -edl - Boot to Emergency DownLoad mode\n"
>  #endif
> +     "reset -c - cold reset if implemented\n"
>       "reset -w - warm reset if implemented"
>  );

The '- reset without level specifier' line reads oddly now that the
level is no longer guaranteed to be cold - perhaps '- reset using the
configured default type'.

> Add reset -c so users can excplicitly request a cold reset when needed.

Typo: excplicitly -> explicitly. Also please use single quotes around
tokens like 'reset -c' per U-Boot convention.

Regards,
Simon

[1] https://patchwork.ozlabs.org/project/uboot/cover/20260519233207.2765755-1-sjg@chromium.org/

Re: [PATCH v3 2/6] reset: Add explicit cold reset support

[dmukhin]

On Mon, Jun 01, 2026 at 08:54:25AM -0600, Simon Glass wrote:
> Hi Denis,
> 
> On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> > reset: Add explicit cold reset support
> >
> > Some prototype boards default to a non-cold reset type, e.g. warm reset.
> >
> > Add reset -c so users can excplicitly request a cold reset when needed.
> >
> > Signed-off-by: Denis Mukhin <dmukhin@ford.com>
> >
> > cmd/boot.c                         |  3 ++-
> >  drivers/sysreset/sysreset-uclass.c | 13 +++++++++++--
> >  2 files changed, 13 insertions(+), 3 deletions(-)
> 
> > diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
> > @@ -174,8 +174,17 @@ int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> >       if (argc > 2)
> >               return CMD_RET_USAGE;
> >
> > -     if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'w') {
> > -             reset_type = SYSRESET_WARM;
> > +     if (argc == 2 && argv[1][0] == '-') {
> > +             switch (argv[1][1]) {
> > +             case 'c':
> > +                     reset_type = SYSRESET_COLD;
> > +                     break;
> > +             case 'w':
> > +                     reset_type = SYSRESET_WARM;
> > +                     break;
> > +             default:
> > +                     return CMD_RET_USAGE;
> > +             }
> >       }
> 
> This regresses reset -edl on Qualcomm. Previously, an unknown -x
> argument fell through to the SYSRESET_CMD_RESET_ARGS path, where
> qcom_psci_sysreset_request_arg() picks up -edl and returns
> -EINPROGRESS. With this change, argv[1][1] == 'e' hits the default
> branch and bails out with CMD_RET_USAGE before sysreset_walk_arg()
> runs, so reset -edl no longer works.
> 
> Please leave reset_type at its default for unrecognised flags (so the
> arg-dispatch path can still claim them), or call sysreset_walk_arg()
> first and only complain if nothing handled the argument. Also,
> matching only argv[1][1] means reset -cx silently behaves like reset
> -c - please tighten with strcmp() or a length check.

Yes, will do; thanks for catching this!

> 
> The could be a good usage for getopt() but sadly it increases code
> size too much [1]
> 
> BTW -edl doesn't follow the normal flags approach, so we should
> probably change that at some point.
> 
> > diff --git a/cmd/boot.c b/cmd/boot.c
> > @@ -59,10 +59,11 @@ U_BOOT_CMD(
> >  U_BOOT_CMD(
> >       reset, 2, 0,    do_reset,
> >       "Perform RESET of the CPU",
> > -     "- cold boot without level specifier\n"
> > +     "- reset without level specifier\n"
> >  #ifdef CONFIG_SYSRESET_QCOM_PSCI
> >       "reset -edl - Boot to Emergency DownLoad mode\n"
> >  #endif
> > +     "reset -c - cold reset if implemented\n"
> >       "reset -w - warm reset if implemented"
> >  );
> 
> The '- reset without level specifier' line reads oddly now that the
> level is no longer guaranteed to be cold - perhaps '- reset using the
> configured default type'.
> 
> > Add reset -c so users can excplicitly request a cold reset when needed.
> 
> Typo: excplicitly -> explicitly. Also please use single quotes around
> tokens like 'reset -c' per U-Boot convention.
> 
> Regards,
> Simon
> 
> [1] https://patchwork.ozlabs.org/project/uboot/cover/20260519233207.2765755-1-sjg@chromium.org/

[PATCH v3 3/6] reset: Print reset type on diagnostic console

[dmukhin]

From: Denis Mukhin <dmukhin@ford.com> 

Add a diagnostic console trace indicating the reset type.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v2:
- n/a

Changes since v1:
- corrected the string representation for SYSRESET_POWER
---
 drivers/sysreset/sysreset-uclass.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
index df68b5c3f9eb..8f49a6093d49 100644
--- a/drivers/sysreset/sysreset-uclass.c
+++ b/drivers/sysreset/sysreset-uclass.c
@@ -22,6 +22,22 @@
 #include <linux/err.h>
 #include <asm/global_data.h>
 
+static const char *get_reset_type_str(enum sysreset_t reset_type)
+{
+	switch (reset_type) {
+	case SYSRESET_WARM:
+		return "warm";
+	case SYSRESET_COLD:
+		return "cold";
+	case SYSRESET_POWER:
+		return "power";
+	case SYSRESET_POWER_OFF:
+		return "power off";
+	default:
+		return "unknown";
+	}
+}
+
 int sysreset_request(struct udevice *dev, enum sysreset_t type)
 {
 	struct sysreset_ops *ops = sysreset_get_ops(dev);
@@ -187,7 +203,7 @@ int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 		}
 	}
 
-	printf("resetting ...\n");
+	printf("resetting (%s)...\n", get_reset_type_str(reset_type));
 	mdelay(100);
 
 #if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_ARGS)
-- 
2.54.0

Re: [PATCH v3 3/6] reset: Print reset type on diagnostic console

[Simon Glass]

Hi Denis,

On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> reset: Print reset type on diagnostic console
>
> Add a diagnostic console trace indicating the reset type.
>
> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
>
> drivers/sysreset/sysreset-uclass.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)

> diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
> @@ -22,6 +22,22 @@
>  #include <linux/err.h>
>  #include <asm/global_data.h>
>
> +static const char *get_reset_type_str(enum sysreset_t reset_type)
> +{
> +     switch (reset_type) {
> +     case SYSRESET_WARM:
> +             return 'warm';
> +     case SYSRESET_COLD:
> +             return 'cold';
> +     case SYSRESET_POWER:
> +             return 'power';
> +     case SYSRESET_POWER_OFF:
> +             return "power off";
> +     default:
> +             return 'unknown';
> +     }
> +}
> +

This is placed outside the #if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET)
block, but its only caller (do_reset()) is inside it. With
CONFIG_SYSRESET_CMD_RESET=n the static function becomes unused and
triggers -Wunused-function. Please move it inside the guard, next to
do_reset()

Regards,
Simon

[PATCH v3 4/6] reset: x86: Use cpu_hlt() in pch_sysreset_power_off()

[dmukhin]

From: Denis Mukhin <dmukhin@ford.com> 

Use cpu_hlt() instead of open-coded "hlt" in pch_sysreset_power_off().

Also, replace the open-coded busy loop in efi_reset_system() and use
cpu_hlt().

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v2:
- n/a

Changes since v1:
- dropped unneeded #include
- corrected the commit message
---
 drivers/sysreset/sysreset_x86.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/sysreset/sysreset_x86.c b/drivers/sysreset/sysreset_x86.c
index c2f28c65280f..afb77d9c5c21 100644
--- a/drivers/sysreset/sysreset_x86.c
+++ b/drivers/sysreset/sysreset_x86.c
@@ -65,7 +65,7 @@ int pch_sysreset_power_off(struct udevice *dev)
 	outl(reg32, pm.base + pm.pm1_cnt_ofs);
 
 	for (;;)
-		asm("hlt");
+		cpu_hlt();
 }
 
 static int x86_sysreset_request(struct udevice *dev, enum sysreset_t type)
@@ -120,7 +120,8 @@ void __efi_runtime EFIAPI efi_reset_system(
 
 	/* TODO EFI_RESET_SHUTDOWN */
 
-	while (1) { }
+	for (;;)
+		cpu_hlt();
 }
 #endif
 
-- 
2.54.0

Re: [PATCH v3 4/6] reset: x86: Use cpu_hlt() in pch_sysreset_power_off()

[Simon Glass]

Hi Denis,

On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> reset: x86: Use cpu_hlt() in pch_sysreset_power_off()
>
> Use cpu_hlt() instead of open-coded 'hlt' in pch_sysreset_power_off().
>
> Also, replace the open-coded busy loop in efi_reset_system() and use
> cpu_hlt().
>
> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
>
> drivers/sysreset/sysreset_x86.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

> diff --git a/drivers/sysreset/sysreset_x86.c b/drivers/sysreset/sysreset_x86.c
> @@ -120,7 +120,8 @@ void __efi_runtime EFIAPI efi_reset_system(
>
>       /* TODO EFI_RESET_SHUTDOWN */
>
> -     while (1) { }
> +     for (;;)
> +             cpu_hlt();
>  }

Just to check - this is an __efi_runtime function, so the body must
not call outside the runtime section after SetVirtualAddressMap().
cpu_hlt() is static inline __always_inline in asm/processor.h so it
expands to a bare hlt here, which is fine. Worth mentioning in the
commit message so the runtime-safety is explicit.

Regards,
Simon

Re: [PATCH v3 4/6] reset: x86: Use cpu_hlt() in pch_sysreset_power_off()

[dmukhin]

On Mon, Jun 01, 2026 at 08:54:48AM -0600, Simon Glass wrote:
> Hi Denis,
> 
> On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> > reset: x86: Use cpu_hlt() in pch_sysreset_power_off()
> >
> > Use cpu_hlt() instead of open-coded 'hlt' in pch_sysreset_power_off().
> >
> > Also, replace the open-coded busy loop in efi_reset_system() and use
> > cpu_hlt().
> >
> > Signed-off-by: Denis Mukhin <dmukhin@ford.com>
> >
> > drivers/sysreset/sysreset_x86.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> Reviewed-by: Simon Glass <sjg@chromium.org>
> 
> > diff --git a/drivers/sysreset/sysreset_x86.c b/drivers/sysreset/sysreset_x86.c
> > @@ -120,7 +120,8 @@ void __efi_runtime EFIAPI efi_reset_system(
> >
> >       /* TODO EFI_RESET_SHUTDOWN */
> >
> > -     while (1) { }
> > +     for (;;)
> > +             cpu_hlt();
> >  }
> 
> Just to check - this is an __efi_runtime function, so the body must
> not call outside the runtime section after SetVirtualAddressMap().
> cpu_hlt() is static inline __always_inline in asm/processor.h so it
> expands to a bare hlt here, which is fine. Worth mentioning in the
> commit message so the runtime-safety is explicit.

I think I will move that efi_reset_system() fixup to a separate patch
with a proper description.

> 
> Regards,
> Simon

[PATCH v3 5/6] docs: reset: document cold reset option

[dmukhin]

From: Denis Mukhin <dmukhin@ford.com> 

Update the reset command documentation to cover `reset -c` and explain
that the default reset type can be overridden through the relevant
Kconfig choice.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v2:
- n/a

Changes since v1:
- new patch
---
 doc/usage/cmd/reset.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/doc/usage/cmd/reset.rst b/doc/usage/cmd/reset.rst
index 79bc8b9deca5..e319d2146caa 100644
--- a/doc/usage/cmd/reset.rst
+++ b/doc/usage/cmd/reset.rst
@@ -12,6 +12,7 @@ Synopsis
 ::
 
     reset
+    reset -c
     reset -w
     reset -edl
 
@@ -21,6 +22,13 @@ Description
 Perform reset of the CPU. By default does COLD reset, which resets CPU,
 DDR and peripherals, on some boards also resets external PMIC.
 
+The default behavior may be overridden via
+CONFIG_SYSRESET_CMD_RESET_DEFAULT_{COLD,WARM,POWER,POWER_OFF}.
+
+-c
+    Do COLD reset: reset CPU and peripheral/DDR; on some boards also resets
+    external PMIC.
+
 -w
     Do WARM reset: reset CPU but keep peripheral/DDR/PMIC active.
 
-- 
2.54.0

Re: [PATCH v3 5/6] docs: reset: document cold reset option

[Simon Glass]

Hi Denis,

On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> docs: reset: document cold reset option
>
> Update the reset command documentation to cover reset -c and explain
> that the default reset type can be overridden through the relevant
> Kconfig choice.
>
> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
>
> doc/usage/cmd/reset.rst | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)

> diff --git a/doc/usage/cmd/reset.rst b/doc/usage/cmd/reset.rst
> @@ -19,6 +19,13 @@ Description
>  Perform reset of the CPU. By default does COLD reset, which resets CPU,
>  DDR and peripherals, on some boards also resets external PMIC.
>
> +The default behavior may be overridden via
> +CONFIG_SYSRESET_CMD_RESET_DEFAULT_{COLD,WARM,POWER,POWER_OFF}.

The two sentences contradict each other - the line above says the
default is always COLD, the new line says it can be anything. Please
rework as 'the default is COLD reset unless overridden by ...'.

> diff --git a/doc/usage/cmd/reset.rst b/doc/usage/cmd/reset.rst
> @@ -19,6 +19,13 @@ Description
> +-c
> +    Do COLD reset: reset CPU and peripheral/DDR; on some boards also resets
> +    external PMIC.
> +
>  -w
>      Do warm WARM, reset CPU but keep peripheral/DDR/PMIC active.

While here, please fix the pre-existing 'Do warm WARM,' typo on -w and
use a consistent form for both entries (e.g. 'Do WARM reset:' / 'Do
COLD reset:'). The new -c text also duplicates the Description
paragraph; a short 'Do COLD reset (same as the default when
CONFIG_SYSRESET_CMD_RESET_DEFAULT_COLD=y)' would avoid the repetition.

> diff --git a/doc/usage/cmd/reset.rst b/doc/usage/cmd/reset.rst
> @@ -11,7 +11,7 @@ Synopsis
>
>  ::
>
> -    reset [-w]
> +    reset [-c|-w]

While here, -edl is documented further down but missing from the
synopsis. Please list it too so the synopsis matches the option list.

Regards,
Simon

[PATCH v3 6/6] tests: reset: add cold/warm reset types

[dmukhin]

From: Denis Mukhin <dmukhin@ford.com> 

Extend reset tests to cover both -c/-w reset command flags.
Make sure sandbox reset tests are passing.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v2:
- dropped sandbox condig for pytests

Changes since v1:
- new patch

Test for sandbox:
./test/py/test.py --bd sandbox --build -k test_reset -v
---
 test/py/tests/test_reset.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/py/tests/test_reset.py b/test/py/tests/test_reset.py
index af079a706647..e1037c963f77 100644
--- a/test/py/tests/test_reset.py
+++ b/test/py/tests/test_reset.py
@@ -52,12 +52,12 @@ def test_reset(ubman):
     test_000_version.test_version(ubman)
 
 @pytest.mark.buildconfigspec('hush_parser')
-def test_reset_w(ubman):
-    """Test the reset -w command in non-JTAG bootmode.
-    It does WARM reset, which resets CPU but keep DDR/peripherals active.
+@pytest.mark.parametrize("reset_type", ["c", "w"])
+def test_reset_type(ubman, reset_type):
+    """Test the reset -{c,w} command in non-JTAG bootmode.
     """
     setup_reset_env(ubman)
-    ubman.run_command('reset -w', wait_for_reboot=True)
+    ubman.run_command(f"reset -{reset_type}", wait_for_reboot=True)
 
     # Checks the u-boot command prompt's functionality after reset
     test_000_version.test_version(ubman)
-- 
2.54.0

Re: [PATCH v3 6/6] tests: reset: add cold/warm reset types

[Simon Glass]

Hi Denis,

On 2026-05-29T03:48:33, None <dmukhin@ford.com> wrote:
> tests: reset: add cold/warm reset types
>
> Extend reset tests to cover both -c/-w reset command flags.
> Make sure sandbox reset tests are passing.
>
> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
>
> test/py/tests/test_reset.py | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

> diff --git a/test/py/tests/test_reset.py b/test/py/tests/test_reset.py
> @@ -52,12 +52,12 @@ def test_reset(ubman):
> +@pytest.mark.parametrize('reset_type', ['c', 'w'])
> +def test_reset_type(ubman, reset_type):
> +    """Test the reset -{c,w} command in non-JTAG bootmode.
>      """
>      setup_reset_env(ubman)
> -    ubman.run_command('reset -w', wait_for_reboot=True)
> +    ubman.run_command(f"reset -{reset_type}", wait_for_reboot=True)

U-Boot uses single quotes throughout ('hush_parser', 'reset -w',
etc.). Please keep that style - @pytest.mark.parametrize('reset_type',
['c', 'w']) and f'reset -{reset_type}'.

Regards,
Simon