diff mbox series

platform/x86: ideapad-laptop: Add has_touchpad_switch

Message ID 20210101061140.27547-1-jiaxun.yang@flygoat.com
State Superseded
Headers show
Series platform/x86: ideapad-laptop: Add has_touchpad_switch | expand

Commit Message

Jiaxun Yang Jan. 1, 2021, 6:11 a.m. UTC
Newer ideapads (e.g.: Yoga 14s, 720S 14) comes with I2C HID
Touchpad and do not use EC to switch touchpad. Reading VPCCMD_R_TOUCHPAD
will return zero thus touchpad may be blocked. Writing VPCCMD_W_TOUCHPAD
may cause a spurious key press.

Add has_touchpad_switch to workaround these machines.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: stable@vger.kernel.org # 5.4+
---
 drivers/platform/x86/ideapad-laptop.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

Comments

Jiaxun Yang Jan. 2, 2021, 2:36 a.m. UTC | #1
在 2021/1/2 上午1:09, Barnabás Pőcze 写道:
> Hi
>
>
> 2021. január 1., péntek 17:08 keltezéssel, Jiaxun Yang írta:
>
>> [...]
>>>> @@ -1006,6 +1018,10 @@ static int ideapad_acpi_add(struct platform_device *pdev)
>>>>   	if (!priv->has_hw_rfkill_switch)
>>>>   		write_ec_cmd(priv->adev->handle, VPCCMD_W_RF, 1);
>>>>
>>>> +	/* The same for Touchpad */
>>>> +	if (!priv->has_touchpad_switch)
>>>> +		write_ec_cmd(priv->adev->handle, VPCCMD_W_TOUCHPAD, 1);
>>>> +
>>> Shouldn't it be the other way around: `if (priv->has_touchpad_switch)`?
>> It is to prevent accidentally disable touchpad on machines that do have EC switch,
>> so it's intentional.
>> [...]
> Sorry, but the explanation not fully clear to me. The commit message seems to
> indicate that some models "do not use EC to switch touchpad", and I take that
> means that reading from VPCCMD_R_TOUCHPAD will not reflect the actual state of the
> touchpad and writing to VPCCMD_W_TOUCHPAD will not change the state of the touchpad.

I'm just trying to prevent removing functionality on machines that 
touchpad can be controlled
by EC but also equipped I2C HID touchpad. At least users will have a 
functional touchpad
after that.

>
> But then why do you still write to VPCCMD_W_TOUCHPAD on devices where supposedly
> this does not have any effect (at least not the desired one)? And the part of the
> code I made my comment about only runs on machines on which the touchpad supposedly
> cannot be controlled by the EC. What am I missing?
>
> And there is the other problem: on some machines, this patch removes working
> functionality.
Yeah that's a problem. I just don't want to repeat the story of rfkill 
whitelist, it ends up with
countless machine to be added.

Maybe I should specify HID of touchpad as well. Two machines that known 
to be problematic
all have ELAN0634 touchpad.

Thanks.

- Jiaxun

>
>
> Regards,
> Barnabás Pőcze
diff mbox series

Patch

diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
index 7598cd46cf60..b6a4db37d0fc 100644
--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -92,6 +92,7 @@  struct ideapad_private {
 	struct dentry *debug;
 	unsigned long cfg;
 	bool has_hw_rfkill_switch;
+	bool has_touchpad_switch;
 	const char *fnesc_guid;
 };
 
@@ -535,7 +536,9 @@  static umode_t ideapad_is_visible(struct kobject *kobj,
 	} else if (attr == &dev_attr_fn_lock.attr) {
 		supported = acpi_has_method(priv->adev->handle, "HALS") &&
 			acpi_has_method(priv->adev->handle, "SALS");
-	} else
+	} else if (attr == &dev_attr_touchpad.attr)
+		supported = priv->has_touchpad_switch;
+	else
 		supported = true;
 
 	return supported ? attr->mode : 0;
@@ -867,6 +870,9 @@  static void ideapad_sync_touchpad_state(struct ideapad_private *priv)
 {
 	unsigned long value;
 
+	if (!priv->has_touchpad_switch)
+		return;
+
 	/* Without reading from EC touchpad LED doesn't switch state */
 	if (!read_ec_data(priv->adev->handle, VPCCMD_R_TOUCHPAD, &value)) {
 		/* Some IdeaPads don't really turn off touchpad - they only
@@ -989,6 +995,12 @@  static int ideapad_acpi_add(struct platform_device *pdev)
 	priv->platform_device = pdev;
 	priv->has_hw_rfkill_switch = dmi_check_system(hw_rfkill_list);
 
+	/* Most ideapads with I2C HID don't use EC touchpad switch */
+	if (acpi_dev_present("PNP0C50", NULL, -1))
+		priv->has_touchpad_switch = false;
+	else
+		priv->has_touchpad_switch = true;
+
 	ret = ideapad_sysfs_init(priv);
 	if (ret)
 		return ret;
@@ -1006,6 +1018,10 @@  static int ideapad_acpi_add(struct platform_device *pdev)
 	if (!priv->has_hw_rfkill_switch)
 		write_ec_cmd(priv->adev->handle, VPCCMD_W_RF, 1);
 
+	/* The same for Touchpad */
+	if (!priv->has_touchpad_switch)
+		write_ec_cmd(priv->adev->handle, VPCCMD_W_TOUCHPAD, 1);
+
 	for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
 		if (test_bit(ideapad_rfk_data[i].cfgbit, &priv->cfg))
 			ideapad_register_rfkill(priv, i);