drm/i915: Write zero to DPLL_MD Reg for non-SDVO output

When the output device is LVDS, maybe the pixel clock of adjusted_mode will be
less than that in mode. In such case it will set the incorrect multipler factor
in DPLL_MD register.
So the dpll_md_reg will be reset when the output type is non-SDVO

https://bugs.freedesktop.org/show_bug.cgi?id=22761

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewd-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Zhao Yakui 2009-09-10 15:45:49 +08:00 committed by Eric Anholt
parent e270846fa7
commit bb66c5122b

View File

@ -2652,9 +2652,12 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
udelay(150);
if (IS_I965G(dev) && !IS_IGDNG(dev)) {
sdvo_pixel_multiply = adjusted_mode->clock / mode->clock;
I915_WRITE(dpll_md_reg, (0 << DPLL_MD_UDI_DIVIDER_SHIFT) |
if (is_sdvo) {
sdvo_pixel_multiply = adjusted_mode->clock / mode->clock;
I915_WRITE(dpll_md_reg, (0 << DPLL_MD_UDI_DIVIDER_SHIFT) |
((sdvo_pixel_multiply - 1) << DPLL_MD_UDI_MULTIPLIER_SHIFT));
} else
I915_WRITE(dpll_md_reg, 0);
} else {
/* write it again -- the BIOS does, after all */
I915_WRITE(dpll_reg, dpll);