[bug report] drm/msm: Add SDM845 DPU support

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Jeykumar Sankaran,

This is a semi-automatic email about new static checker warnings.

The patch 25fdd5933e4c: "drm/msm: Add SDM845 DPU support" from Jun
27, 2018, leads to the following Smatch complaint:

    drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c:422 _dpu_hw_sspp_setup_scaler3()
    warn: variable dereferenced before check 'ctx->cap->sblk' (see line 421)

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c
   420		(void)pe;
                ^^^^^^^^^
You should file a bug report with your compiler devs instead of adding
these sorts of statements to your code.  This function is used as a
function pointer so unused parameters are normal.

   421		if (_sspp_subblk_offset(ctx, DPU_SSPP_SCALER_QSEED3, &idx) || !sspp
                    ^^^^^^^^^^^^^^^^^^^^
The _sspp_subblk_offset() dereferenced "ctx" before it is checked and
then it also derefereces "ctx->cap->sblk" without checking.

   422			|| !scaler3_cfg || !ctx || !ctx->cap || !ctx->cap->sblk)
                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
So these will have already crashed before we reach this point.

   423			return;
   424	

regards,
dan carpenter