From: Ben Widawsky <benjamin.widawsky@xxxxxxxxx> Not sure if this is needed or not. The code still falls back to a potentially bad value if PIPE_A was not set. Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx> Signed-off-by: Wayne Boyer <wayne.boyer@xxxxxxxxx> Change-Id: I54eb5d4d9fd93e86878c9fa1daec19bdb6b3bd0b Reviewed-on: https://chromium-review.googlesource.com/196605 Reviewed-by: Aaron Durbin <adurbin@xxxxxxxxxxxx> Tested-by: Wayne Boyer <wayne.boyer@xxxxxxxxx> Commit-Queue: Wayne Boyer <wayne.boyer@xxxxxxxxx> Conflicts: drivers/gpu/drm/i915/intel_panel.c --- drivers/gpu/drm/i915/intel_panel.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 40e0cb08..b3327d0 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -1080,15 +1080,24 @@ static int vlv_setup_backlight(struct intel_connector *connector) u32 ctl, ctl2, val; for_each_pipe(pipe) { - u32 cur_val = I915_READ(VLV_BLC_PWM_CTL(pipe)); + u32 duty = I915_READ(VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK; + u32 freq = I915_READ(VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK; - /* Skip if the modulation freq is already set */ - if (cur_val & ~BACKLIGHT_DUTY_CYCLE_MASK) + if (freq) { + /* Skip if the modulation freq is already set */ continue; + } + + if (WARN_ON(pipe == PIPE_A)) { + /* Assume BLC for pipe A is the default. Therefore, A + * must be non-zero. */ + freq = (VLV_DEFAULT_BACKLIGHT_MOD_FREQ << 16); + } else + freq = I915_READ(VLV_BLC_PWM_CTL(PIPE_A)) & ~BACKLIGHT_DUTY_CYCLE_MASK; - cur_val &= BACKLIGHT_DUTY_CYCLE_MASK; - I915_WRITE(VLV_BLC_PWM_CTL(pipe), (0xf42 << 16) | - cur_val); + if (WARN_ON(freq == 0)) + freq = (VLV_DEFAULT_BACKLIGHT_MOD_FREQ << 16); + I915_WRITE(VLV_BLC_PWM_CTL(pipe), freq | duty); } ctl2 = I915_READ(VLV_BLC_PWM_CTL2(PIPE_A)); -- 1.7.9.5 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
