drm/panel: himax-hx83102: Check for errors on the NOP in prepare()

The mipi_dsi_dcs_nop() function returns an error but we weren't
checking it in hx83102_prepare(). Add a check. This is highly unlikely
to matter in practice. If the NOP failed then likely later MIPI
commands would fail too.

Found by code inspection.

Fixes: 0ef94554dc40 ("drm/panel: himax-hx83102: Break out as separate driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240517143643.7.I3fae28745bf2cacd8dac04d7a06daea50e233f46@changeid
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517143643.7.I3fae28745bf2cacd8dac04d7a06daea50e233f46@changeid

diff --git a/drivers/gpu/drm/panel/panel-himax-hx83102.c b/drivers/gpu/drm/panel/panel-himax-hx83102.c
index 4ac7f9d8b232be08a902ff6a8d7cf5a35abaa073..1ba623e4192436638c1c6dd3847f9e4d21107559 100644 (file)
--- a/drivers/gpu/drm/panel/panel-himax-hx83102.c
+++ b/drivers/gpu/drm/panel/panel-himax-hx83102.c
@@ -547,7 +547,11 @@ static int hx83102_prepare(struct drm_panel *panel)
 
        usleep_range(10000, 11000);
 
-       mipi_dsi_dcs_nop(ctx->dsi);
+       ret = mipi_dsi_dcs_nop(ctx->dsi);
+       if (ret < 0) {
+               dev_err(dev, "Failed to send NOP: %d\n", ret);
+               goto poweroff;
+       }
        usleep_range(1000, 2000);
 
        gpiod_set_value(ctx->enable_gpio, 1);