diff options
| author | James Ausmus <james.ausmus@intel.com> | 2017-11-30 18:17:00 -0800 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2017-12-01 09:44:03 -0800 |
| commit | 23a7068ec581fcc6fb61039448632d25987b1fae (patch) | |
| tree | 3599bee2938908a29b9e967f0de3a05dca0e1cbd | |
| parent | fb6db0f5bf1d4d3a4af6242e287fa795221ec5b8 (diff) | |
drm/i915/cnl: Mask previous DDI - PLL mapping
Without masking out the old value, we can end up pointing the DDI to a
disabled PLL, which makes the system fall over. Mask out the previous
value before setting the PLL to DDI mapping.
This can be observed by running igt/testdisplay with both an eDP and
HDMI/DP output active.
v2: Add the Bugzilla link
Fixes: 555e38d273172 ("drm/i915/cnl: DDI - PLL mapping")
Testcase: igt/testdisplay
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103997
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: James Ausmus <james.ausmus@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Tested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171201021700.13504-1-james.ausmus@intel.com
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ddi.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index 48ba9b7fdc78..369f780588fb 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -2098,6 +2098,7 @@ static void intel_ddi_clk_select(struct intel_encoder *encoder, if (IS_CANNONLAKE(dev_priv)) { /* Configure DPCLKA_CFGCR0 to map the DPLL to the DDI. */ val = I915_READ(DPCLKA_CFGCR0); + val &= ~DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port); val |= DPCLKA_CFGCR0_DDI_CLK_SEL(pll->id, port); I915_WRITE(DPCLKA_CFGCR0, val); |