From 5ebd50d3948ee596db02399a09b4561ed82aee57 Mon Sep 17 00:00:00 2001 From: Lee Shawn C Date: Wed, 8 Sep 2021 19:56:04 +0800 Subject: [PATCH] drm/i915/dsi: refine send MIPI DCS command sequence According to chapter "Sending Commands to the Panel" in bspec #29738 and #49188. If driver try to send DCS long pakcet, we have to program TX payload register at first. And configure TX header HW register later. DSC long packet would not be sent properly if we don't follow this sequence. Cc: Ville Syrjala Cc: Jani Nikula Cc: Vandita Kulkarni Cc: Cooper Chiou Cc: William Tseng Signed-off-by: Lee Shawn C Reviewed-by: Vandita Kulkarni Signed-off-by: Vandita Kulkarni Link: https://patchwork.freedesktop.org/patch/msgid/20210908115607.9633-3-shawn.c.lee@intel.com --- drivers/gpu/drm/i915/display/icl_dsi.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c index 4428900..060bc8f 100644 --- a/drivers/gpu/drm/i915/display/icl_dsi.c +++ b/drivers/gpu/drm/i915/display/icl_dsi.c @@ -1831,11 +1831,6 @@ static ssize_t gen11_dsi_host_transfer(struct mipi_dsi_host *host, if (msg->flags & MIPI_DSI_MSG_USE_LPM) enable_lpdt = true; - /* send packet header */ - ret = dsi_send_pkt_hdr(intel_dsi_host, dsi_pkt, enable_lpdt); - if (ret < 0) - return ret; - /* only long packet contains payload */ if (mipi_dsi_packet_format_is_long(msg->type)) { ret = dsi_send_pkt_payld(intel_dsi_host, dsi_pkt); @@ -1843,6 +1838,11 @@ static ssize_t gen11_dsi_host_transfer(struct mipi_dsi_host *host, return ret; } + /* send packet header */ + ret = dsi_send_pkt_hdr(intel_dsi_host, dsi_pkt, enable_lpdt); + if (ret < 0) + return ret; + //TODO: add payload receive code if needed ret = sizeof(dsi_pkt.header) + dsi_pkt.payload_length; -- 2.7.4