From 535a65db484ff4e4654a037f2ea7e1ff21431b77 Mon Sep 17 00:00:00 2001 From: Tomeu Vizoso Date: Mon, 30 Mar 2015 10:33:03 +0200 Subject: [PATCH] drm/tegra: sor: Reset during initialization As there isn't a way for the firmware on the Nyan Chromebooks to hand over the display to the kernel, and the kernel isn't redoing the whole configuration at present. With this patch, the SOR is brought to a known state and we get correct display on every boot. Signed-off-by: Tomeu Vizoso Signed-off-by: Thierry Reding --- drivers/gpu/drm/tegra/sor.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c index 41c5a6ed2c36..7591d8901f9a 100644 --- a/drivers/gpu/drm/tegra/sor.c +++ b/drivers/gpu/drm/tegra/sor.c @@ -1512,12 +1512,30 @@ static int tegra_sor_init(struct host1x_client *client) } } + /* + * XXX: Remove this reset once proper hand-over from firmware to + * kernel is possible. + */ + err = reset_control_assert(sor->rst); + if (err < 0) { + dev_err(sor->dev, "failed to assert SOR reset: %d\n", err); + return err; + } + err = clk_prepare_enable(sor->clk); if (err < 0) { dev_err(sor->dev, "failed to enable clock: %d\n", err); return err; } + usleep_range(1000, 3000); + + err = reset_control_deassert(sor->rst); + if (err < 0) { + dev_err(sor->dev, "failed to deassert SOR reset: %d\n", err); + return err; + } + err = clk_prepare_enable(sor->clk_safe); if (err < 0) return err; -- 2.20.1