drm/i915: Change N divider minimum from 3 to 2 for gen2

Bruno Prémont has a 855 machine with a 1400x1050 LVDS screen.

The VBT mode is as follows:
0:"1400x1050" 0 108000 1400 1416 1528 1688 1050 1051 1054 1066 0x8 0xa

The BIOS uses the following DPLL settings:
DPLL = 0x90020000
FP0 = 0x2140e
FP1 = 0x21207

We can't generate that pixel clock currently as we're limiting the N
divider to at least 3, whereas the BIOS uses a value of 2.

Let's reduce the N minimum to 2 and see what happens.

Cc: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8c4e384b8ae1de95cda2752667f3d0e74fe7ae16..efc3391dfac53e975d21434b8a5121612a30f49a 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -91,7 +91,7 @@ intel_fdi_link_freq(struct drm_device *dev)
 static const intel_limit_t intel_limits_i8xx_dac = {
        .dot = { .min = 25000, .max = 350000 },
        .vco = { .min = 930000, .max = 1400000 },
-       .n = { .min = 3, .max = 16 },
+       .n = { .min = 2, .max = 16 },
        .m = { .min = 96, .max = 140 },
        .m1 = { .min = 18, .max = 26 },
        .m2 = { .min = 6, .max = 16 },
@@ -104,7 +104,7 @@ static const intel_limit_t intel_limits_i8xx_dac = {
 static const intel_limit_t intel_limits_i8xx_dvo = {
        .dot = { .min = 25000, .max = 350000 },
        .vco = { .min = 930000, .max = 1400000 },
-       .n = { .min = 3, .max = 16 },
+       .n = { .min = 2, .max = 16 },
        .m = { .min = 96, .max = 140 },
        .m1 = { .min = 18, .max = 26 },
        .m2 = { .min = 6, .max = 16 },
@@ -117,7 +117,7 @@ static const intel_limit_t intel_limits_i8xx_dvo = {
 static const intel_limit_t intel_limits_i8xx_lvds = {
        .dot = { .min = 25000, .max = 350000 },
        .vco = { .min = 930000, .max = 1400000 },
-       .n = { .min = 3, .max = 16 },
+       .n = { .min = 2, .max = 16 },
        .m = { .min = 96, .max = 140 },
        .m1 = { .min = 18, .max = 26 },
        .m2 = { .min = 6, .max = 16 },