Hi Eray, On 10/29/22 14:03, Eray Orçunus wrote: > IdeaPads dropped support for VPCCMD_W_CAMERA somewhere between 2014-2016, > none of the IdeaPads produced after that I tested supports it. Fortunately > I found a way to check it; if the DSDT has camera device(s) defined, it > shouldn't have working VPCCMD_W_CAMERA, thus camera_power shouldn't be > exposed to sysfs. To accomplish this, walk the ACPI namespace in > ideapad_check_features and check the devices starting with "CAM". > Tested on 520-15IKB and Legion Y520, which successfully didn't expose > the camera_power attribute. > > Link: https://www.spinics.net/lists/platform-driver-x86/msg26147.html > Signed-off-by: Eray Orçunus <erayorcunus@xxxxxxxxx> > --- > drivers/platform/x86/ideapad-laptop.c | 52 ++++++++++++++++++++++++++- > 1 file changed, 51 insertions(+), 1 deletion(-) > > diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c > index f3d4f2beda07..e8c088e7a53d 100644 > --- a/drivers/platform/x86/ideapad-laptop.c > +++ b/drivers/platform/x86/ideapad-laptop.c > @@ -149,6 +149,7 @@ struct ideapad_private { > bool fn_lock : 1; > bool hw_rfkill_switch : 1; > bool kbd_bl : 1; > + bool cam_ctrl_via_ec : 1; > bool touchpad_ctrl_via_ec : 1; > bool usb_charging : 1; > } features; > @@ -163,6 +164,24 @@ static bool no_bt_rfkill; > module_param(no_bt_rfkill, bool, 0444); > MODULE_PARM_DESC(no_bt_rfkill, "No rfkill for bluetooth."); > > +static acpi_status acpi_find_device_callback(acpi_handle handle, u32 level, > + void *context, void **return_value) > +{ > + struct acpi_buffer ret_buf; > + char buffer[8]; > + > + ret_buf.length = sizeof(buffer); > + ret_buf.pointer = buffer; > + > + if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_SINGLE_NAME, &ret_buf))) > + if (strstarts(ret_buf.pointer, context)) { > + *return_value = handle; > + return AE_CTRL_TERMINATE; > + } > + > + return AE_OK; > +} > + > /* > * ACPI Helpers > */ > @@ -675,7 +694,7 @@ static umode_t ideapad_is_visible(struct kobject *kobj, > bool supported = true; > > if (attr == &dev_attr_camera_power.attr) > - supported = test_bit(CFG_CAP_CAM_BIT, &priv->cfg); > + supported = priv->features.cam_ctrl_via_ec; > else if (attr == &dev_attr_conservation_mode.attr) > supported = priv->features.conservation_mode; > else if (attr == &dev_attr_fan_mode.attr) > @@ -1527,6 +1546,37 @@ static void ideapad_check_features(struct ideapad_private *priv) > > priv->features.hw_rfkill_switch = dmi_check_system(hw_rfkill_list); > > + /* > + * Some IdeaPads have camera switch via EC (mostly older ones), > + * some don't. Fortunately we know that if DSDT contains device > + * object for the camera, camera isn't switchable via EC. > + * So, let's walk the namespace and try to find CAM* object. > + * If we can't find it, set cam_ctrl_via_ec to true. > + */ > + > + priv->features.cam_ctrl_via_ec = false; There is no need to explicitly set this to false since the entire struct is allocated with kzalloc() and a bunch of other features flags are also not explicitly set to false. Please drop this line. > + > + if (test_bit(CFG_CAP_CAM_BIT, &priv->cfg)) { > + acpi_handle temp_handle = NULL; > + acpi_handle pci_handle; > + acpi_status status; > + > + status = acpi_get_handle(handle, "^^^", &pci_handle); > + if (ACPI_SUCCESS(status)) { > + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, pci_handle, > + ACPI_UINT32_MAX, > + acpi_find_device_callback, > + NULL, "CAM", > + &temp_handle); Why not just use acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ... ? The PCI root is usually pretty much the only object under the root anyways and this way you can avoid the acpi_get_handle() call + its error handling, so using ACPI_ROOT_OBJECT would lead to a nice cleanup. > + > + if (ACPI_SUCCESS(status) && temp_handle == NULL) > + priv->features.cam_ctrl_via_ec = true; > + > + } else > + dev_warn(&priv->platform_device->dev, > + "Could not find PCI* node in the namespace\n"); > + } > + > /* Most ideapads with ELAN0634 touchpad don't use EC touchpad switch */ > priv->features.touchpad_ctrl_via_ec = !acpi_dev_present("ELAN0634", NULL, -1); > Regards, Hans
