Re: [Bug 106031] Regression in 4.2.x: in airplane mode each time I open my laptop lid

[Gabriele Mazzotta <gabriele.mzt@gmail.com>]

On 22/10/2015 10:51, Pali Rohár wrote:
> On Thursday 22 October 2015 10:26:47 Gabriele Mazzotta wrote:
>> I'll see if I can find a batter way to deal with this problem,
>> dell-laptop can detect the presence of an hardware switch.
>
> dell-rbtn.ko has acpi method CRBT which returns if notebook has hw switch or
> toggle key.
>
> And rfkill implementation in dell-laptop.ko does not work correctly on
> XPS machines. And because userspace implementation of smbios works fine,
> I think that problem is in kernel driver rather in BIOS/firmware...

I was thinking about something such as the following, which should favor
the hardware slider when available. This should work if my assumption is
correct, that is the laptops with a working RBTN method are the ones
having problems.

diff --git a/drivers/platform/x86/dell-rbtn.c 
b/drivers/platform/x86/dell-rbtn.c
index cd410e3..cf3c11c 100644
--- a/drivers/platform/x86/dell-rbtn.c
+++ b/drivers/platform/x86/dell-rbtn.c
@@ -321,6 +321,7 @@ static int rbtn_add(struct acpi_device *device)
  	struct rbtn_data *rbtn_data;
  	enum rbtn_type type;
  	int ret = 0;
+	bool has_hardware_slider; /* get this with SMI */

  	type = rbtn_check(device);
  	if (type == RBTN_UNKNOWN) {
@@ -328,7 +329,7 @@ static int rbtn_add(struct acpi_device *device)
  		return -EINVAL;
  	}

-	ret = rbtn_acquire(device, true);
+	ret = rbtn_acquire(device, !has_hardware_slider);
  	if (ret < 0) {
  		dev_err(&device->dev, "Cannot enable device\n");
  		return ret;
@@ -343,7 +344,10 @@ static int rbtn_add(struct acpi_device *device)

  	switch (rbtn_data->type) {
  	case RBTN_TOGGLE:
-		ret = rbtn_input_init(rbtn_data);
+		if (has_hardware_slider)
+			ret = 0;
+		else
+			ret = rbtn_input_init(rbtn_data);
  		break;
  	case RBTN_SLIDER:
  		if (auto_remove_rfkill && rbtn_chain_head.head)