From 398314516446ad12959e29556a3bafb6534a1065 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 1 Mar 2017 15:15:03 +0200 Subject: [PATCH] drm/i915/dsi: Document always using v3 SHUTDOWN / MIPI_SEQ_DISPLAY_OFF order According to the spec for v2 VBTs we should call MIPI_SEQ_DISPLAY_OFF before sending SHUTDOWN, where as for v3 VBTs we should send SHUTDOWN first. Since the v2 order has known issues, we use the v3 order everywhere, add a comment documenting this. Signed-off-by: Hans de Goede Reviewed-by: Bob Paauwe Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1488374106-4949-8-git-send-email-jani.nikula@intel.com --- drivers/gpu/drm/i915/intel_dsi.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c index b132841587cc..5a50645c3a37 100644 --- a/drivers/gpu/drm/i915/intel_dsi.c +++ b/drivers/gpu/drm/i915/intel_dsi.c @@ -872,6 +872,11 @@ static void intel_dsi_pre_disable(struct intel_encoder *encoder, I915_WRITE(MIPI_DEVICE_READY(port), 0); } + /* + * According to the spec we should send SHUTDOWN before + * MIPI_SEQ_DISPLAY_OFF only for v3+ VBTs, but field testing + * has shown that the v3 sequence works for v2 VBTs too + */ if (is_vid_mode(intel_dsi)) { /* Send Shutdown command to the panel in LP mode */ for_each_dsi_port(port, intel_dsi->ports) -- 2.20.1