Hi, On 3/7/23 12:38, Hans de Goede wrote: > Make apple-gmux backlight registration honor the acpi_backlight=... > kernel commandline option which is used to select the backlight > control method on x86/ACPI devices. > > Reported-and-tested-by: Aditya Garg <gargaditya08@xxxxxxxx> > Link: https://lore.kernel.org/platform-driver-x86/BM1PR01MB0931B467250831916F7C55B3B8A59@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> I've added this to my review-hans (soon to be for-next) branch now. Regards, Hans > --- > drivers/platform/x86/apple-gmux.c | 59 +++++++++++++++++-------------- > 1 file changed, 33 insertions(+), 26 deletions(-) > > diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c > index 757fd71c900f..787cf2a7e268 100644 > --- a/drivers/platform/x86/apple-gmux.c > +++ b/drivers/platform/x86/apple-gmux.c > @@ -23,6 +23,7 @@ > #include <linux/pci.h> > #include <linux/vga_switcheroo.h> > #include <linux/debugfs.h> > +#include <acpi/video.h> > #include <asm/io.h> > > /** > @@ -783,6 +784,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > struct backlight_properties props; > struct backlight_device *bdev; > u8 ver_major, ver_minor, ver_release; > + bool register_bdev = true; > int ret = -ENXIO; > acpi_status status; > unsigned long long gpe; > @@ -859,33 +861,38 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > props.type = BACKLIGHT_PLATFORM; > props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS); > > - /* > - * Currently it's assumed that the maximum brightness is less than > - * 2^24 for compatibility with old gmux versions. Cap the max > - * brightness at this value, but print a warning if the hardware > - * reports something higher so that it can be fixed. > - */ > - if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS)) > - props.max_brightness = GMUX_MAX_BRIGHTNESS; > - > - bdev = backlight_device_register("gmux_backlight", &pnp->dev, > - gmux_data, &gmux_bl_ops, &props); > - if (IS_ERR(bdev)) { > - ret = PTR_ERR(bdev); > - goto err_unmap; > - } > - > - gmux_data->bdev = bdev; > - bdev->props.brightness = gmux_get_brightness(bdev); > - backlight_update_status(bdev); > +#if IS_REACHABLE(CONFIG_ACPI_VIDEO) > + register_bdev = acpi_video_get_backlight_type() == acpi_backlight_apple_gmux; > +#endif > + if (register_bdev) { > + /* > + * Currently it's assumed that the maximum brightness is less than > + * 2^24 for compatibility with old gmux versions. Cap the max > + * brightness at this value, but print a warning if the hardware > + * reports something higher so that it can be fixed. > + */ > + if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS)) > + props.max_brightness = GMUX_MAX_BRIGHTNESS; > + > + bdev = backlight_device_register("gmux_backlight", &pnp->dev, > + gmux_data, &gmux_bl_ops, &props); > + if (IS_ERR(bdev)) { > + ret = PTR_ERR(bdev); > + goto err_unmap; > + } > > - /* > - * The backlight situation on Macs is complicated. If the gmux is > - * present it's the best choice, because it always works for > - * backlight control and supports more levels than other options. > - * Disable the other backlight choices. > - */ > - apple_bl_unregister(); > + gmux_data->bdev = bdev; > + bdev->props.brightness = gmux_get_brightness(bdev); > + backlight_update_status(bdev); > + > + /* > + * The backlight situation on Macs is complicated. If the gmux is > + * present it's the best choice, because it always works for > + * backlight control and supports more levels than other options. > + * Disable the other backlight choices. > + */ > + apple_bl_unregister(); > + } > > gmux_data->power_state = VGA_SWITCHEROO_ON; >
