Hello Arthur Heymans,
I'd like you to do a code review. Please visit
https://review.coreboot.org/c/libgfxinit/+/35779
to review the following change.
Change subject: gma g45 config: Limit HDMI rate to 165MHz ......................................................................
gma g45 config: Limit HDMI rate to 165MHz
Tests with a 3440x1440 pixel display have shown that the dot clock was chosen much too high (we got either 720x1440 at half the rate or a completely garbled picture). Turns out, Linux' i915 limits the clock to the original DVI's 165MHz for 4th gen and earlier, so we'll do that too. This resulted in a stable picture with 3440x1440 @ 31Hz (the display even synchronized better on this than the configuration chosen by i915).
Change-Id: I30cb67feedd776148457101d1ca3e3b8538e672f Signed-off-by: Nico Huber nico.h@gmx.de --- M common/hw-gfx-gma-config.ads.template 1 file changed, 4 insertions(+), 1 deletion(-)
git pull ssh://review.coreboot.org:29418/libgfxinit refs/changes/79/35779/1
diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template index 8711e54..f9d67aa 100644 --- a/common/hw-gfx-gma-config.ads.template +++ b/common/hw-gfx-gma-config.ads.template @@ -322,7 +322,10 @@
-- FIXME: Unknown for Broxton, Linux' i915 contains a fixme too :-D HDMI_Max_Clock_24bpp : constant Frequency_Type := - (if Haswell_On then 300_000_000 else 225_000_000); + (case Gen is + when Generation'First .. G45 => 165_000_000, + when Ironlake => 225_000_000, + when Haswell .. Generation'Last => 300_000_000);
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Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/libgfxinit/+/35779 )
Change subject: gma g45 config: Limit HDMI rate to 165MHz ......................................................................
Patch Set 1:
Just curious, how do you tell libgfxinit mainboard has DVI-(I/D) instead of HDMI connector? The frequency specs are different.
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/libgfxinit/+/35779 )
Change subject: gma g45 config: Limit HDMI rate to 165MHz ......................................................................
Patch Set 1:
Just curious, how do you tell libgfxinit mainboard has DVI-(I/D) instead of HDMI connector? The frequency specs are different.
Um, to be honest, we don't handle that (yet). So far, the builds are board specific, so I'd add it as config setting.
Arthur Heymans has posted comments on this change. ( https://review.coreboot.org/c/libgfxinit/+/35779 )
Change subject: gma g45 config: Limit HDMI rate to 165MHz ......................................................................
Patch Set 1: Code-Review+2
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/libgfxinit/+/35779 )
Change subject: gma g45 config: Limit HDMI rate to 165MHz ......................................................................
Patch Set 1: Verified+1
Nico Huber has submitted this change. ( https://review.coreboot.org/c/libgfxinit/+/35779 )
Change subject: gma g45 config: Limit HDMI rate to 165MHz ......................................................................
gma g45 config: Limit HDMI rate to 165MHz
Tests with a 3440x1440 pixel display have shown that the dot clock was chosen much too high (we got either 720x1440 at half the rate or a completely garbled picture). Turns out, Linux' i915 limits the clock to the original DVI's 165MHz for 4th gen and earlier, so we'll do that too. This resulted in a stable picture with 3440x1440 @ 31Hz (the display even synchronized better on this than the configuration chosen by i915).
Change-Id: I30cb67feedd776148457101d1ca3e3b8538e672f Signed-off-by: Nico Huber nico.h@gmx.de Reviewed-on: https://review.coreboot.org/c/libgfxinit/+/35779 Reviewed-by: Arthur Heymans arthur@aheymans.xyz --- M common/hw-gfx-gma-config.ads.template 1 file changed, 4 insertions(+), 1 deletion(-)
Approvals: Nico Huber: Verified Arthur Heymans: Looks good to me, approved
diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template index d5bd2ba..e4e557a 100644 --- a/common/hw-gfx-gma-config.ads.template +++ b/common/hw-gfx-gma-config.ads.template @@ -322,7 +322,10 @@
-- FIXME: Unknown for Broxton, Linux' i915 contains a fixme too :-D HDMI_Max_Clock_24bpp : constant Frequency_Type := - (if Haswell_On then 300_000_000 else 225_000_000); + (case Gen is + when Generation'First .. G45 => 165_000_000, + when Ironlake => 225_000_000, + when Haswell .. Generation'Last => 300_000_000);
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Arthur Heymans (Code Review) -
Kyösti Mälkki (Code Review)
-
Nico Huber (Code Review)