From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> [ Upstream commit cd0e0ca69109d025b1a1b6609f70682db62138b0 ] The ARRAY_SIZE() macro is type size_t. If s6e8aa0_dcs_read() returns a negative error code, then "ret < ARRAY_SIZE(id)" is false because the negative error code is type promoted to a high positive value. Fixes: 02051ca06371 ("drm/panel: add S6E8AA0 driver") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20180704093807.s3lqsb2v6dg2k43d@kili.mountain Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/gpu/drm/panel/panel-s6e8aa0.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panel/panel-s6e8aa0.c b/drivers/gpu/drm/panel/panel-s6e8aa0.c index b5217fe37f02..0e46b6762cf0 100644 --- a/drivers/gpu/drm/panel/panel-s6e8aa0.c +++ b/drivers/gpu/drm/panel/panel-s6e8aa0.c @@ -835,7 +835,7 @@ static void s6e8aa0_read_mtp_id(struct s6e8aa0 *ctx) int ret, i; ret = s6e8aa0_dcs_read(ctx, 0xd1, id, ARRAY_SIZE(id)); - if (ret < ARRAY_SIZE(id) || id[0] == 0x00) { + if (ret < 0 || ret < ARRAY_SIZE(id) || id[0] == 0x00) { dev_err(ctx->dev, "read id failed\n"); ctx->error = -EIO; return; -- 2.17.1