[bug-report] Smatch warns unsigned comparison with zero in dw_mipi_dsi_rockchip_set_lcdsel()

[Harshit Mogalapalli]

Hi,

Smatch warns:
drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c:755 
dw_mipi_dsi_rockchip_set_lcdsel() warn: unsigned 
'dsi->cdata->lcdsel_grf_reg'
is never less than zero.

static void dw_mipi_dsi_rockchip_set_lcdsel(struct dw_mipi_dsi_rockchip 
*dsi,
                                            int mux)
{
        if (dsi->cdata->lcdsel_grf_reg < 0)
                regmap_write(dsi->grf_regmap, dsi->cdata->lcdsel_grf_reg,
                        mux ? dsi->cdata->lcdsel_lit : 
dsi->cdata->lcdsel_big);
}

'dsi->cdata->lcdsel_grf_reg' is of u32 type, it can never be less than zero.
So the above if condition is an impossible one.

Note: 'lcdsel_grf_reg' is set to -1 at other places.


Thanks,
Harshit