Re: [PATCH] drm/omap: dsi: fix unsigned expression compared with zero

From: Laurent Pinchart
Date: Sat Mar 13 2021 - 21:21:16 EST


Hi Junlin,

Thank you for the patch.

On Fri, Mar 12, 2021 at 03:14:45PM +0800, angkery wrote:
> From: Junlin Yang <yangjunlin@xxxxxxxxxx>
>
> r is "u32" always >= 0,mipi_dsi_create_packet may return little than zero.
> so r < 0 condition is never accessible.
>
> Fixes coccicheck warnings:
> ./drivers/gpu/drm/omapdrm/dss/dsi.c:2155:5-6:
> WARNING: Unsigned expression compared with zero: r < 0
>
> Signed-off-by: Junlin Yang <yangjunlin@xxxxxxxxxx>

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

Tomi, will you take this in your tree ?

> ---
> drivers/gpu/drm/omapdrm/dss/dsi.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> index 8e11612..b31d750 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> @@ -2149,11 +2149,12 @@ static int dsi_vc_send_short(struct dsi_data *dsi, int vc,
> const struct mipi_dsi_msg *msg)
> {
> struct mipi_dsi_packet pkt;
> + int ret;
> u32 r;
>
> - r = mipi_dsi_create_packet(&pkt, msg);
> - if (r < 0)
> - return r;
> + ret = mipi_dsi_create_packet(&pkt, msg);
> + if (ret < 0)
> + return ret;
>
> WARN_ON(!dsi_bus_is_locked(dsi));
>

--
Regards,

Laurent Pinchart