drm/bridge/synopsys: dsi: allow sending longer LP commands

Current code does not properly computes the max length of LP
commands that can be send during H or V sync, and rely on static
values.
Limiting the max LP length to 4 byte during the V-sync is overly
conservative.

Relax the limit and allows longer LP commands (16 bytes) to be
sent during V-sync.
Signed-off-by: Antonio Borneo <antonio.borneo@st.com>
Tested-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701143131.841-1-yannick.fertre@st.com

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -361,6 +361,15 @@ static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
 	bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
 	u32 val = 0;
 
+	/*
+	 * TODO dw drv improvements
+	 * largest packet sizes during hfp or during vsa/vpb/vfp
+	 * should be computed according to byte lane, lane number and only
+	 * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
+	 */
+	dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(16)
+		  | INVACT_LPCMD_TIME(4));
+
 	if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
 		val |= ACK_RQST_EN;
 	if (lpm)
@@ -619,14 +628,6 @@ static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
 	dsi_write(dsi, DSI_DPI_VCID, DPI_VCID(dsi->channel));
 	dsi_write(dsi, DSI_DPI_COLOR_CODING, color);
 	dsi_write(dsi, DSI_DPI_CFG_POL, val);
-	/*
-	 * TODO dw drv improvements
-	 * largest packet sizes during hfp or during vsa/vpb/vfp
-	 * should be computed according to byte lane, lane number and only
-	 * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
-	 */
-	dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(4)
-		  | INVACT_LPCMD_TIME(4));
 }
 
 static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)