[PATCH 2/2] drm/i915/dsi: Return early if MIPI control unchanged

[Mika Kahola]

Return early if we try to send the same MIPI control two ro more
time in a row.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102404
Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_dsi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index b48b9b7..6001753 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -258,12 +258,12 @@ static int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs,
 	else
 		cmd |= DPI_LP_MODE;
 
-	/* clear bit */
-	I915_WRITE(MIPI_INTR_STAT(port), SPL_PKT_SENT_INTERRUPT);
-
 	/* XXX: old code skips write if control unchanged */
 	if (cmd == I915_READ(MIPI_DPI_CONTROL(port)))
-		DRM_ERROR("Same special packet %02x twice in a row.\n", cmd);
+		return 0;
+
+	/* clear bit */
+	I915_WRITE(MIPI_INTR_STAT(port), SPL_PKT_SENT_INTERRUPT);
 
 	I915_WRITE(MIPI_DPI_CONTROL(port), cmd);
 
-- 
2.7.4