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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>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	Daniel Vetter <daniel@ffwll.ch>,
	David Airlie <airlied@gmail.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Shuijing Li <shuijing.li@mediatek.com>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Xinlei Lee <xinlei.lee@mediatek.com>,
	dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 3/8] drm/panel: boe-tv101wum-nl6: Check for errors on the NOP in prepare()
Date: Fri, 17 May 2024 14:36:38 -0700
Message-ID: <20240517143643.3.Ibffbaa5b4999ac0e55f43bf353144433b099d727@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 boe_panel_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: 812562b8d881 ("drm/panel: boe-tv101wum-nl6: Fine tune the panel power sequence")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
index 028625d2d37d..f7beace455c3 100644
--- a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
+++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
@@ -1456,7 +1456,11 @@ static int boe_panel_prepare(struct drm_panel *panel)
 	usleep_range(10000, 11000);
 
 	if (boe->desc->lp11_before_reset) {
-		mipi_dsi_dcs_nop(boe->dsi);
+		ret = mipi_dsi_dcs_nop(boe->dsi);
+		if (ret < 0) {
+			dev_err(&boe->dsi->dev, "Failed to send NOP: %d\n", ret);
+			goto poweroff;
+		}
 		usleep_range(1000, 2000);
 	}
 	gpiod_set_value(boe->enable_gpio, 1);
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog