From a4c9c85da2fe26bebf940449d475724e7e9c4561 Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Tue, 10 Nov 2020 11:21:56 +0000 Subject: [PATCH 332/634] drm/panel/raspberrypi-ts: Insert delay before polling for startup state In switching to the hardware I2C controller there is an issue where we seem to not get back the correct state from the Pi touchscreen. Insert a delay before polling to avoid this condition. Signed-off-by: Dave Stevenson --- drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c index c5621f07158e..07013bfddf42 100644 --- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c +++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c @@ -299,6 +299,7 @@ static int rpi_touchscreen_enable(struct drm_panel *panel) int i; rpi_touchscreen_i2c_write(ts, REG_POWERON, 1); + usleep_range(20000, 25000); /* Wait for nPWRDWN to go low to indicate poweron is done. */ for (i = 0; i < 100; i++) { if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1) -- 2.33.1