From 65cd2b3fa521d1abec13dd36bf1bfc8f2469d8bc Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 22 May 2015 11:22:32 +0300 Subject: [PATCH] drm/i915: Fix 852GM/GMV cdclk MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit It seems 852GM/GMV uses a different HPLLCC encoding than the other 85x platforms. For 852GM/GMV cdclk is always 133MHz. Try to detect that using the PCI revision (sinc the device ID seems useless for that). I'm not at all sure this is a good idea, but according to the specs it should work. v2: Rebased to the latest v3: Rebased to the latest Signed-off-by: Ville Syrjälä (v1) Signed-off-by: Mika Kahola Acked-by: Damien Lespiau Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 0b1d8d68ad2b..73a46149564a 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6826,6 +6826,14 @@ static int i85x_get_display_clock_speed(struct drm_device *dev) { u16 hpllcc = 0; + /* + * 852GM/852GMV only supports 133 MHz and the HPLLCC + * encoding is different :( + * FIXME is this the right way to detect 852GM/852GMV? + */ + if (dev->pdev->revision == 0x1) + return 133333; + pci_bus_read_config_word(dev->pdev->bus, PCI_DEVFN(0, 3), HPLLCC, &hpllcc); -- 2.20.1