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 <[email protected]> Suggested-by: Douglas Anderson <[email protected]> Signed-off-by: Linus Walleij <[email protected]> --- drivers/gpu/drm/drm_mipi_dbi.c | 2 +- include/drm/drm_mipi_dbi.h | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c index 3854fb9798e9..c7c1b75df190 100644 --- a/drivers/gpu/drm/drm_mipi_dbi.c +++ b/drivers/gpu/drm/drm_mipi_dbi.c @@ -645,7 +645,7 @@ static int mipi_dbi_poweron_reset_conditional(struct mipi_dbi_dev *dbidev, bool return 1; mipi_dbi_hw_reset(dbi); - ret = mipi_dbi_command(dbi, MIPI_DCS_SOFT_RESET); + ret = mipi_dbi_command_buf(dbi, MIPI_DCS_SOFT_RESET, NULL, 0); if (ret) { DRM_DEV_ERROR(dev, "Failed to send reset command (%d)\n", ret); if (dbidev->regulator) diff --git a/include/drm/drm_mipi_dbi.h b/include/drm/drm_mipi_dbi.h index f543d6e3e822..2057ad32760c 100644 --- a/include/drm/drm_mipi_dbi.h +++ b/include/drm/drm_mipi_dbi.h @@ -183,7 +183,10 @@ 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)); \ + int ret; \ + ret = mipi_dbi_command_stackbuf(dbi, cmd, d, ARRAY_SIZE(d)); \ + if (ret) \ + pr_err_ratelimited("MIPI DBI: error %d when sending command\n", ret); \ }) #ifdef CONFIG_DEBUG_FS -- 2.31.1
