* [PATCH] hwmon: (gpd-fan) Reset both fans to automatic on duo boards
@ 2026-09-26 0:13 ` Alexei Solcanu via B4 Relay
0 siblings, 0 replies; 4+ messages in thread
From: Alexei Solcanu @ 2026-09-26 0:13 UTC (permalink / raw)
To: Guenter Roeck, Cryolitia PukNgae
Cc: linux-hwmon, linux-kernel, Antheas Kapenekakis, Alexei Solcanu
On boards using gpd_duo_drvdata (GPD Duo, GPD Win 5), writing
pwm1_enable=2 only returns the first fan to EC control. The second fan
keeps its last manual duty cycle, e.g. full speed after pwm1=255, so a
fan control tool that exits leaves it running at that speed.
gpd_duo_write_pwm() writes both fan registers (pwm_write and
pwm_write + 1), but switching to automatic only clears pwm_write.
Also clear pwm_write + 1, so both fans return to EC control.
Tested on a GPD Win 5 (G1618-05). Not tested on the GPD Duo.
Fixes: 0ab88e239439 ("hwmon: add GPD devices sensor driver")
Assisted-by: LLM
Signed-off-by: Alexei Solcanu <alexei.solcanu@pm.me>
---
Both fans were set to full speed (pwm1_enable=1, pwm1=255), then
switched to automatic (pwm1_enable=2). Values read from the EC 15
seconds later:
0x047A 0x047B fan 1 fan 2
without patch 0x00 0xf4 2542 rpm 6379 rpm
with patch 0x00 0x00 2545 rpm 2560 rpm
Fan 2's RPM, found by probing, is at EC 0x0476/0x0477.
---
drivers/hwmon/gpd-fan.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
index ed212615b2f..b3b75f99f58 100644
--- a/drivers/hwmon/gpd-fan.c
+++ b/drivers/hwmon/gpd-fan.c
@@ -444,6 +444,7 @@ static void gpd_duo_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABL
break;
case AUTOMATIC:
gpd_ecram_write(data->drvdata, data->drvdata->pwm_write, 0);
+ gpd_ecram_write(data->drvdata, data->drvdata->pwm_write + 1, 0);
break;
}
}
---
base-commit: 3cbb5f15e464583e59c8501a7085ec12b53e23ac
change-id: 20260925-gpd-fan-duo-auto-871de9e006dc
Best regards,
--
Alexei Solcanu <alexei.solcanu@pm.me>
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH] hwmon: (gpd-fan) Reset both fans to automatic on duo boards
@ 2026-09-26 0:13 ` Alexei Solcanu via B4 Relay
0 siblings, 0 replies; 4+ messages in thread
From: Alexei Solcanu via B4 Relay @ 2026-09-26 0:13 UTC (permalink / raw)
To: Guenter Roeck, Cryolitia PukNgae
Cc: linux-hwmon, linux-kernel, Antheas Kapenekakis, Alexei Solcanu
From: Alexei Solcanu <alexei.solcanu@pm.me>
On boards using gpd_duo_drvdata (GPD Duo, GPD Win 5), writing
pwm1_enable=2 only returns the first fan to EC control. The second fan
keeps its last manual duty cycle, e.g. full speed after pwm1=255, so a
fan control tool that exits leaves it running at that speed.
gpd_duo_write_pwm() writes both fan registers (pwm_write and
pwm_write + 1), but switching to automatic only clears pwm_write.
Also clear pwm_write + 1, so both fans return to EC control.
Tested on a GPD Win 5 (G1618-05). Not tested on the GPD Duo.
Fixes: 0ab88e239439 ("hwmon: add GPD devices sensor driver")
Assisted-by: LLM
Signed-off-by: Alexei Solcanu <alexei.solcanu@pm.me>
---
Both fans were set to full speed (pwm1_enable=1, pwm1=255), then
switched to automatic (pwm1_enable=2). Values read from the EC 15
seconds later:
0x047A 0x047B fan 1 fan 2
without patch 0x00 0xf4 2542 rpm 6379 rpm
with patch 0x00 0x00 2545 rpm 2560 rpm
Fan 2's RPM, found by probing, is at EC 0x0476/0x0477.
---
drivers/hwmon/gpd-fan.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
index ed212615b2f..b3b75f99f58 100644
--- a/drivers/hwmon/gpd-fan.c
+++ b/drivers/hwmon/gpd-fan.c
@@ -444,6 +444,7 @@ static void gpd_duo_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABL
break;
case AUTOMATIC:
gpd_ecram_write(data->drvdata, data->drvdata->pwm_write, 0);
+ gpd_ecram_write(data->drvdata, data->drvdata->pwm_write + 1, 0);
break;
}
}
---
base-commit: 3cbb5f15e464583e59c8501a7085ec12b53e23ac
change-id: 20260925-gpd-fan-duo-auto-871de9e006dc
Best regards,
--
Alexei Solcanu <alexei.solcanu@pm.me>
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] hwmon: (gpd-fan) Reset both fans to automatic on duo boards
2026-09-26 0:13 ` Alexei Solcanu via B4 Relay
(?)
@ 2026-09-26 0:22 ` sashiko-bot
-1 siblings, 0 replies; 4+ messages in thread
From: sashiko-bot @ 2026-09-26 0:22 UTC (permalink / raw)
To: Alexei Solcanu; +Cc: linux-hwmon
> From: Alexei Solcanu <alexei.solcanu@pm.me>
>
> On boards using gpd_duo_drvdata (GPD Duo, GPD Win 5), writing
> pwm1_enable=2 only returns the first fan to EC control. The second fan
> keeps its last manual duty cycle, e.g. full speed after pwm1=255, so a
> fan control tool that exits leaves it running at that speed.
>
> gpd_duo_write_pwm() writes both fan registers (pwm_write and
> pwm_write + 1), but switching to automatic only clears pwm_write.
> Also clear pwm_write + 1, so both fans return to EC control.
>
> Tested on a GPD Win 5 (G1618-05). Not tested on the GPD Duo.
>
> Fixes: 0ab88e239439 ("hwmon: add GPD devices sensor driver")
> Assisted-by: LLM
> Signed-off-by: Alexei Solcanu <alexei.solcanu@pm.me>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260925-gpd-fan-duo-auto-v1-1-29bb670b3331@pm.me?part=1
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] hwmon: (gpd-fan) Reset both fans to automatic on duo boards
2026-09-26 0:13 ` Alexei Solcanu via B4 Relay
(?)
(?)
@ 2026-09-26 1:46 ` Guenter Roeck
-1 siblings, 0 replies; 4+ messages in thread
From: Guenter Roeck @ 2026-09-26 1:46 UTC (permalink / raw)
To: alexei.solcanu
Cc: Cryolitia PukNgae, linux-hwmon, linux-kernel, Antheas Kapenekakis
On Fri, Sep 25, 2026 at 08:13:26PM -0400, Alexei Solcanu via B4 Relay wrote:
> From: Alexei Solcanu <alexei.solcanu@pm.me>
>
> On boards using gpd_duo_drvdata (GPD Duo, GPD Win 5), writing
> pwm1_enable=2 only returns the first fan to EC control. The second fan
> keeps its last manual duty cycle, e.g. full speed after pwm1=255, so a
> fan control tool that exits leaves it running at that speed.
>
> gpd_duo_write_pwm() writes both fan registers (pwm_write and
> pwm_write + 1), but switching to automatic only clears pwm_write.
> Also clear pwm_write + 1, so both fans return to EC control.
>
> Tested on a GPD Win 5 (G1618-05). Not tested on the GPD Duo.
>
> Fixes: 0ab88e239439 ("hwmon: add GPD devices sensor driver")
> Assisted-by: LLM
> Signed-off-by: Alexei Solcanu <alexei.solcanu@pm.me>
> ---
> Both fans were set to full speed (pwm1_enable=1, pwm1=255), then
> switched to automatic (pwm1_enable=2). Values read from the EC 15
> seconds later:
>
> 0x047A 0x047B fan 1 fan 2
> without patch 0x00 0xf4 2542 rpm 6379 rpm
> with patch 0x00 0x00 2545 rpm 2560 rpm
>
> Fan 2's RPM, found by probing, is at EC 0x0476/0x0477.
If this system has two fans, why does it register only one
fan and pwm channel ? This seems conceptually wrong.
Guenter
> ---
> drivers/hwmon/gpd-fan.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
> index ed212615b2f..b3b75f99f58 100644
> --- a/drivers/hwmon/gpd-fan.c
> +++ b/drivers/hwmon/gpd-fan.c
> @@ -444,6 +444,7 @@ static void gpd_duo_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABL
> break;
> case AUTOMATIC:
> gpd_ecram_write(data->drvdata, data->drvdata->pwm_write, 0);
> + gpd_ecram_write(data->drvdata, data->drvdata->pwm_write + 1, 0);
> break;
> }
> }
>
> ---
> base-commit: 3cbb5f15e464583e59c8501a7085ec12b53e23ac
> change-id: 20260925-gpd-fan-duo-auto-871de9e006dc
>
> Best regards,
> --
> Alexei Solcanu <alexei.solcanu@pm.me>
>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-09-26 1:46 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-09-26 0:13 [PATCH] hwmon: (gpd-fan) Reset both fans to automatic on duo boards Alexei Solcanu
2026-09-26 0:13 ` Alexei Solcanu via B4 Relay
2026-09-26 0:22 ` sashiko-bot
2026-09-26 1:46 ` Guenter Roeck
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.