From: Diogo Ivo Date: Mon, 28 Nov 2022 16:28:49 +0000 (+0000) Subject: drm/tegra: dsi: Clear enable register if powered by bootloader X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b22fd0b9639ed61e379b3b9bba00629ebf8e6946;p=linux.git drm/tegra: dsi: Clear enable register if powered by bootloader In cases where the DSI module is left on by the bootloader some panels may fail to initialize if the enable register is not cleared before the panel's initialization sequence is sent, so clear it if that is the case. Signed-off-by: Diogo Ivo Signed-off-by: Thierry Reding --- diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c index 49f0bc270e147..a9870c8283749 100644 --- a/drivers/gpu/drm/tegra/dsi.c +++ b/drivers/gpu/drm/tegra/dsi.c @@ -912,6 +912,15 @@ static void tegra_dsi_encoder_enable(struct drm_encoder *encoder) u32 value; int err; + /* If the bootloader enabled DSI it needs to be disabled + * in order for the panel initialization commands to be + * properly sent. + */ + value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL); + + if (value & DSI_POWER_CONTROL_ENABLE) + tegra_dsi_disable(dsi); + err = tegra_dsi_prepare(dsi); if (err < 0) { dev_err(dsi->dev, "failed to prepare: %d\n", err);