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author | Hans de Goede <hdegoede@redhat.com> | 2020-11-18 15:40:58 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-19 20:27:32 +0300 |
commit | 54c9246a47fa8559c3ec6da2048e976a4b8750f6 (patch) | |
tree | ee41dbf7ab2b26c0d63ada556006305dd2265018 /drivers/gpu/drm/i915/display/vlv_dsi.c | |
parent | f6de06406411bfae3c1b7d4dad3fbab10a81e426 (diff) | |
download | linux-54c9246a47fa8559c3ec6da2048e976a4b8750f6.tar.xz |
drm/i915/dsi: Use unconditional msleep for the panel_on_delay when there is no reset-deassert MIPI-sequence
commit 00cb645fd7e29bdd20967cd20fa8f77bcdf422f9 upstream.
Commit 25b4620ee822 ("drm/i915/dsi: Skip delays for v3 VBTs in vid-mode")
added an intel_dsi_msleep() helper which skips sleeping if the
MIPI-sequences have a version of 3 or newer and the panel is in vid-mode;
and it moved a bunch of msleep-s over to this new helper.
This was based on my reading of the big comment around line 730 which
starts with "Panel enable/disable sequences from the VBT spec.",
where the "v3 video mode seq" column does not have any wait t# entries.
Given that this code has been used on a lot of different devices without
issues until now, it seems that my interpretation of the spec here is
mostly correct.
But now I have encountered one device, an Acer Aspire Switch 10 E
SW3-016, where the panel will not light up unless we do actually honor the
panel_on_delay after exexuting the MIPI_SEQ_PANEL_ON sequence.
What seems to set this model apart is that it is lacking a
MIPI_SEQ_DEASSERT_RESET sequence, which is where the power-on
delay usually happens.
Fix the panel not lighting up on this model by using an unconditional
msleep(panel_on_delay) instead of intel_dsi_msleep() when there is
no MIPI_SEQ_DEASSERT_RESET sequence.
Fixes: 25b4620ee822 ("drm/i915/dsi: Skip delays for v3 VBTs in vid-mode")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201118124058.26021-1-hdegoede@redhat.com
(cherry picked from commit 6fdb335f1c9c0845b50625de1624d8445c4c4a07)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu/drm/i915/display/vlv_dsi.c')
-rw-r--r-- | drivers/gpu/drm/i915/display/vlv_dsi.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c index 5e5522923b1e..690239d3f2e5 100644 --- a/drivers/gpu/drm/i915/display/vlv_dsi.c +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c @@ -812,10 +812,20 @@ static void intel_dsi_pre_enable(struct intel_atomic_state *state, intel_dsi_prepare(encoder, pipe_config); intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_POWER_ON); - intel_dsi_msleep(intel_dsi, intel_dsi->panel_on_delay); - /* Deassert reset */ - intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET); + /* + * Give the panel time to power-on and then deassert its reset. + * Depending on the VBT MIPI sequences version the deassert-seq + * may contain the necessary delay, intel_dsi_msleep() will skip + * the delay in that case. If there is no deassert-seq, then an + * unconditional msleep is used to give the panel time to power-on. + */ + if (dev_priv->vbt.dsi.sequence[MIPI_SEQ_DEASSERT_RESET]) { + intel_dsi_msleep(intel_dsi, intel_dsi->panel_on_delay); + intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET); + } else { + msleep(intel_dsi->panel_on_delay); + } if (IS_GEMINILAKE(dev_priv)) { glk_cold_boot = glk_dsi_enable_io(encoder); |