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From: Douglas Anderson <dianders@chromium.org>
To: Neil Armstrong <neil.armstrong@linaro.org>,
	Jessica Zhang <quic_jesszhan@quicinc.com>,
	Sam Ravnborg <sam@ravnborg.org>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Douglas Anderson <dianders@chromium.org>,
	Cong Yang <yangcong5@huaqin.corp-partner.google.com>,
	Daniel Vetter <daniel@ffwll.ch>,
	David Airlie <airlied@gmail.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 7/8] drm/panel: himax-hx83102: Check for errors on the NOP in prepare()
Date: Fri, 17 May 2024 14:36:42 -0700
Message-ID: <20240517143643.7.I3fae28745bf2cacd8dac04d7a06daea50e233f46@changeid>
In-Reply-To: <20240517213712.3135166-1-dianders@chromium.org>
References: <20240517213712.3135166-1-dianders@chromium.org>
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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>
---

 drivers/gpu/drm/panel/panel-himax-hx83102.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-himax-hx83102.c b/drivers/gpu/drm/panel/panel-himax-hx83102.c
index 4ac7f9d8b232..1ba623e41924 100644
--- 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);
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog