From: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Date: Mon, 18 Feb 2019 05:40:49 +0000 (+0900)
Subject: drm/panel: Add error handling for write of dsi
X-Git-Tag: accepted/tizen/unified/20200709.164653~196
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b4921efb66c467960e549d43809fefd666b58e1f;p=platform%2Fkernel%2Flinux-rpi.git

drm/panel: Add error handling for write of dsi

There is a problem that dsi write timeout even when dsi interrupt is
activated by adding 'ignore_lcd=1' flag to config.txt. Add error
handling to write once more when timeout occurs.

Change-Id: If1deb9753a02a3082e7a1ba59ee20531828447d9
Signed-off-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
---

diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
index 2aa89ea..46ec225 100644
--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -237,6 +237,7 @@ static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 
 static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 {
+	int ret;
 	u8 msg[] = {
 		reg,
 		reg >> 8,
@@ -246,7 +247,14 @@ static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 		val >> 24,
 	};
 
-	mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
+	ret = mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
+	/*
+	 * WORKAROUND: There is a problem that timeout occurs even though
+	 * dsi interrupts occur. Add error handling to write once more
+	 * when timeout occurs.
+	 */
+	if (ret == -ETIMEDOUT)
+		mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
 
 	return 0;
 }