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.
Drop the only user in DRM using mipi_dbi_command() and actually checking
the error explicitly, let it use mipi_dbi_command_buf() directly
instead.
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@xxxxxxxxxxx>
Suggested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v2->v3:
- Make the macro actually return the error value if need be, by
putting a single ret; at the end of the macro. (Neat trick from
StackOverflow!)
- Switch the site where I switched mipi_dbi_command() to
mipi_dbi_command_buf() back to what it was.
- Print the failed command in the error message.
- Put the dbi in (parens) since drivers/gpu/drm/tiny/st7586.c was
passing &dbidev->dbi as parameter to mipi_dbi_command()
and this would expand to
struct device *dev = &&dbidev->dbi->spi->dev
which can't be parsed but
struct device *dev = &(&dbidev->dbi)->spi-dev;
should work. I hope.
ChangeLog v1->v2:
- Fish out the struct device * from the DBI SPI client and use
that to print the errors associated with the SPI device.
---
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
--
2.31.1
