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drm/i915: Honour LVDS sync polarity from EDID 

The i915 driver normally assumes the video bios has configured several
of the LVDS panel registers, and it just inherits the values. If the
vbios has not run, several of these will need to be setup. So we need to
check that the LVDS sync polarity is correctly configured per any
available modelines (e.g. EDID) and adjust if not, issuing a warning as
we do.

Signed-off-by: Mark Hayter <mdhayter@chromium.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Bryan Freed 2011-01-12 13:43:19 -08:00 committed by Chris Wilson
parent ccab5c8275
commit aa9b500ddf
2 changed files with 21 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/gpu/drm/i915/i915_reg.h
View File

@ -1437,6 +1437,10 @@
#define LVDS_PIPEB_SELECT (1 << 30)
/* LVDS dithering flag on 965/g4x platform */
#define LVDS_ENABLE_DITHER (1 << 25)
/* LVDS sync polarity flags. Set to invert (i.e. negative) */
#define LVDS_VSYNC_POLARITY (1 << 21)
#define LVDS_HSYNC_POLARITY (1 << 20)
/* Enable border for unscaled (or aspect-scaled) display */
#define LVDS_BORDER_ENABLE (1 << 15)
/*

17
drivers/gpu/drm/i915/intel_display.c
View File

@ -4304,6 +4304,7 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
int ret;
struct fdi_m_n m_n = {0};
u32 reg, temp;
u32 lvds_sync = 0;
int target_clock;
drm_vblank_pre_modeset(dev, pipe);
@ -4755,6 +4756,22 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
else
temp &= ~LVDS_ENABLE_DITHER;
}
if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
lvds_sync |= LVDS_HSYNC_POLARITY;
if (adjusted_mode->flags & DRM_MODE_FLAG_NVSYNC)
lvds_sync |= LVDS_VSYNC_POLARITY;
if ((temp & (LVDS_HSYNC_POLARITY | LVDS_VSYNC_POLARITY))
!= lvds_sync) {
char flags[2] = "-+";
DRM_INFO("Changing LVDS panel from "
"(%chsync, %cvsync) to (%chsync, %cvsync)\n",
flags[!(temp & LVDS_HSYNC_POLARITY)],
flags[!(temp & LVDS_VSYNC_POLARITY)],
flags[!(lvds_sync & LVDS_HSYNC_POLARITY)],
flags[!(lvds_sync & LVDS_VSYNC_POLARITY)]);
temp &= ~(LVDS_HSYNC_POLARITY | LVDS_VSYNC_POLARITY);
temp |= lvds_sync;
}
I915_WRITE(reg, temp);
}