Use the GENMASK helper instead of custom calculations to generate masks,
It also helps the readability.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
                        writesl(ss->base + SS_RXFIFO, op->buf, nwait);
                        op->byte_count += 4 * nwait;
                }
+
                nbw = op->len - 4 * nwait;
-               wb = *(u32 *)(op->buf + nwait * 4);
-               wb &= (0xFFFFFFFF >> (4 - nbw) * 8);
+               if (nbw) {
+                       wb = *(u32 *)(op->buf + nwait * 4);
+                       wb &= GENMASK((nbw * 8) - 1, 0);
 
-               op->byte_count += nbw;
+                       op->byte_count += nbw;
+               }
        }
 
        /* write the remaining bytes of the nbw buffer */