From: Alex Deucher <alexander.deucher@xxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 201bb62402e0227375c655446ea04fcd0acf7287 upstream. If the value in the scratch register is 0, set it to the max level. This fixes an issue where the console fb blanking code calls back into the backlight driver on unblank and then sets the backlight level to 0 after the driver has already set the mode and enabled the backlight. bugs: https://bugs.freedesktop.org/show_bug.cgi?id=81382 https://bugs.freedesktop.org/show_bug.cgi?id=70207 Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Tested-by: David Heidelberger <david.heidelberger@xxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/gpu/drm/radeon/atombios_encoders.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c index 583345636d4b..6a965172d8dd 100644 --- a/drivers/gpu/drm/radeon/atombios_encoders.c +++ b/drivers/gpu/drm/radeon/atombios_encoders.c @@ -183,7 +183,6 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder, struct backlight_properties props; struct radeon_backlight_privdata *pdata; struct radeon_encoder_atom_dig *dig; - u8 backlight_level; char bl_name[16]; /* Mac laptops with multiple GPUs use the gmux driver for backlight @@ -222,12 +221,17 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder, pdata->encoder = radeon_encoder; - backlight_level = radeon_atom_get_backlight_level_from_reg(rdev); - dig = radeon_encoder->enc_priv; dig->bl_dev = bd; bd->props.brightness = radeon_atom_backlight_get_brightness(bd); + /* Set a reasonable default here if the level is 0 otherwise + * fbdev will attempt to turn the backlight on after console + * unblanking and it will try and restore 0 which turns the backlight + * off again. + */ + if (bd->props.brightness == 0) + bd->props.brightness = RADEON_MAX_BL_LEVEL; bd->props.power = FB_BLANK_UNBLANK; backlight_update_status(bd); -- 2.0.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html