[PATCH v2 2/4] gpu/drm: tegra: dsi: move prepare function at the top of encoder enable

[Svyatoslav Ryhel]

The tegra_dsi_prepare function performs hardware setup and should be
called before any register readings or there will be a risk of device
hangup on register access. To avoid this situation, tegra_dsi_prepare must
be called at the beginning of tegra_dsi_encoder_enable.

Signed-off-by: Svyatoslav Ryhel <clamo...@gmail.com>
---
 drivers/gpu/drm/tegra/dsi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
index 278bf2c85524..8e80c7efe8b4 100644
--- a/drivers/gpu/drm/tegra/dsi.c
+++ b/drivers/gpu/drm/tegra/dsi.c
@@ -914,6 +914,12 @@ static void tegra_dsi_encoder_enable(struct drm_encoder 
*encoder)
        u32 value;
        int err;
 
+       err = tegra_dsi_prepare(dsi);
+       if (err < 0) {
+               dev_err(dsi->dev, "failed to prepare: %d\n", err);
+               return;
+       }
+
        /* If the bootloader enabled DSI it needs to be disabled
         * in order for the panel initialization commands to be
         * properly sent.
@@ -923,12 +929,6 @@ static void tegra_dsi_encoder_enable(struct drm_encoder 
*encoder)
        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);
-               return;
-       }
-
        state = tegra_dsi_get_state(dsi);
 
        tegra_dsi_set_timeout(dsi, state->bclk, state->vrefresh);
-- 
2.48.1