From f6dfc22a52584ffc728e4f890828df05c2b2cbe1 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@linaro.org>
Date: Fri, 2 Jul 2021 15:56:01 +0200
Subject: drm/dbi: Print errors for mipi_dbi_command()
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Git-commit: 3f5aa5ac0b0f9704f0c60f5fbbbcdc8c043d6eb6
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

The macro mipi_dbi_command() does not report errors unless you wrap it
in another macro to do the error reporting.

Report a rate-limited error so we know what is going on.

After this any code wishing to send command arrays can rely on
mipi_dbi_command() providing an appropriate error message if something
goes wrong.

Suggested-by: Noralf Trønnes <noralf@tronnes.org>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702135601.3952726-1-linus.walleij@linaro.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 include/drm/drm_mipi_dbi.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/drm/drm_mipi_dbi.h b/include/drm/drm_mipi_dbi.h
index f543d6e3e822..05e194958265 100644
--- a/include/drm/drm_mipi_dbi.h
+++ b/include/drm/drm_mipi_dbi.h
@@ -183,7 +183,12 @@ int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb,
 #define mipi_dbi_command(dbi, cmd, seq...) \
 ({ \
 	const u8 d[] = { seq }; \
-	mipi_dbi_command_stackbuf(dbi, cmd, d, ARRAY_SIZE(d)); \
+	struct device *dev = &(dbi)->spi->dev;	\
+	int ret; \
+	ret = mipi_dbi_command_stackbuf(dbi, cmd, d, ARRAY_SIZE(d)); \
+	if (ret) \
+		dev_err_ratelimited(dev, "error %d when sending command %#02x\n", ret, cmd); \
+	ret; \
 })
 
 #ifdef CONFIG_DEBUG_FS
-- 
2.38.1