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| author | Hans de Goede <hdegoede@redhat.com> | 2016-12-02 15:29:04 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-03-16 02:26:38 +0000 |
| commit | 12d4dffb0d8b11d946e4077c672c544a7e1673c0 (patch) | |
| tree | 3cb7cd85b6df2205c7185dd96d189bac68519dd2 /drivers/gpu | |
| parent | adfffd77aa5c89984e21d5e3b2c8c7ab1dc1256c (diff) | |
| download | linux-stable-12d4dffb0d8b11d946e4077c672c544a7e1673c0.tar.gz linux-stable-12d4dffb0d8b11d946e4077c672c544a7e1673c0.tar.bz2 linux-stable-12d4dffb0d8b11d946e4077c672c544a7e1673c0.zip | |
drm/i915/dsi: Do not clear DPOUNIT_CLOCK_GATE_DISABLE from vlv_init_display_clock_gating
commit bb98e72adaf9d19719aba35f802d4836f5d5176c upstream.
On my Cherrytrail CUBE iwork8 Air tablet PIPE-A would get stuck on loading
i915 at boot 1 out of every 3 boots, resulting in a non functional LCD.
Once the i915 driver has successfully loaded, the panel can be disabled /
enabled without hitting this issue.
The getting stuck is caused by vlv_init_display_clock_gating() clearing
the DPOUNIT_CLOCK_GATE_DISABLE bit in DSPCLK_GATE_D when called from
chv_pipe_power_well_ops.enable() on driver load, while a pipe is enabled
driving the DSI LCD by the BIOS.
Clearing this bit while DSI is in use is a known issue and
intel_dsi_pre_enable() / intel_dsi_post_disable() already set / clear it
as appropriate.
This commit modifies vlv_init_display_clock_gating() to leave the
DPOUNIT_CLOCK_GATE_DISABLE bit alone fixing the pipe getting stuck.
Changes in v2:
-Replace PIPE-A with "a pipe" or "the pipe" in the commit msg and
comment
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97330
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161202142904.25613-1-hdegoede@redhat.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
(cherry picked from commit 721d484563e1a51ada760089c490cbc47e909756)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_pm.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 5010e2c32c23..aa83a835965c 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -5346,7 +5346,16 @@ static void valleyview_init_clock_gating(struct drm_device *dev) DRM_DEBUG_DRIVER("Current CD clock rate: %d MHz", dev_priv->vlv_cdclk_freq); - I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE); + /* + * On driver load, a pipe may be active and driving a DSI display. + * Preserve DPOUNIT_CLOCK_GATE_DISABLE to avoid the pipe getting stuck + * (and never recovering) in this case. intel_dsi_post_disable() will + * clear it when we turn off the display. + */ + val = I915_READ(DSPCLK_GATE_D); + val &= DPOUNIT_CLOCK_GATE_DISABLE; + val |= VRHUNIT_CLOCK_GATE_DISABLE; + I915_WRITE(DSPCLK_GATE_D, val); /* WaDisableEarlyCull:vlv */ I915_WRITE(_3D_CHICKEN3, |