From: Thierry Reding <treding@xxxxxxxxxx> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 4f250706211cdb949f7580d4fe4dd1fd646de693 ] If the DSI output isn't connected, then mdfld_dsi_encoder_get_pipe() will return -1. The mdfld_dsi_dp_mode_set() function doesn't properly check for this condition and causes the following compiler warnings: CC drivers/gpu/drm/gma500/mdfld_dsi_dpi.o drivers/gpu/drm/gma500/mdfld_dsi_dpi.c: In function ‘mdfld_dsi_dpi_mode_set’: drivers/gpu/drm/gma500/mdfld_dsi_dpi.c:828:35: warning: array subscript is below array bounds [-Warray-bounds] u32 pipeconf = dev_priv->pipeconf[pipe]; ^ drivers/gpu/drm/gma500/mdfld_dsi_dpi.c:829:33: warning: array subscript is below array bounds [-Warray-bounds] u32 dspcntr = dev_priv->dspcntr[pipe]; ^ Fix this by checking for a valid pipe before indexing the pipeconf and dspcntr arrays. Cc: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx> Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/1450178476-26284-2-git-send-email-boris.brezillon@xxxxxxxxxxxxxxxxxx Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/gpu/drm/gma500/mdfld_dsi_dpi.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/gma500/mdfld_dsi_dpi.c b/drivers/gpu/drm/gma500/mdfld_dsi_dpi.c index d4813e03f5ee..00275c3856ce 100644 --- a/drivers/gpu/drm/gma500/mdfld_dsi_dpi.c +++ b/drivers/gpu/drm/gma500/mdfld_dsi_dpi.c @@ -821,14 +821,18 @@ void mdfld_dsi_dpi_mode_set(struct drm_encoder *encoder, struct drm_device *dev = dsi_config->dev; struct drm_psb_private *dev_priv = dev->dev_private; int pipe = mdfld_dsi_encoder_get_pipe(dsi_encoder); - u32 pipeconf_reg = PIPEACONF; u32 dspcntr_reg = DSPACNTR; + u32 pipeconf, dspcntr; - u32 pipeconf = dev_priv->pipeconf[pipe]; - u32 dspcntr = dev_priv->dspcntr[pipe]; u32 mipi = MIPI_PORT_EN | PASS_FROM_SPHY_TO_AFE | SEL_FLOPPED_HSTX; + if (WARN_ON(pipe < 0)) + return; + + pipeconf = dev_priv->pipeconf[pipe]; + dspcntr = dev_priv->dspcntr[pipe]; + if (pipe) { pipeconf_reg = PIPECCONF; dspcntr_reg = DSPCCNTR; -- 2.14.1