desc = dmaengine_prep_slave_sg(channel,
                                        (struct scatterlist *)pio,
                                        ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
-       if (!desc) {
-               pr_err("step 1 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [2] send out the COMMAND + ADDRESS string stored in @buffer */
        sgl = &this->cmd_sgl;
        desc = dmaengine_prep_slave_sg(channel,
                                sgl, 1, DMA_MEM_TO_DEV,
                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-
-       if (!desc) {
-               pr_err("step 2 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [3] submit the DMA */
        set_dma_type(this, DMA_FOR_COMMAND);
        pio[1] = 0;
        desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
                                        ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
-       if (!desc) {
-               pr_err("step 1 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [2] send DMA request */
        prepare_data_dma(this, DMA_TO_DEVICE);
        desc = dmaengine_prep_slave_sg(channel, &this->data_sgl,
                                        1, DMA_MEM_TO_DEV,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-       if (!desc) {
-               pr_err("step 2 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
+
        /* [3] submit the DMA */
        set_dma_type(this, DMA_FOR_WRITE_DATA);
        return start_dma_without_bch_irq(this, desc);
        desc = dmaengine_prep_slave_sg(channel,
                                        (struct scatterlist *)pio,
                                        ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
-       if (!desc) {
-               pr_err("step 1 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [2] : send DMA request */
        prepare_data_dma(this, DMA_FROM_DEVICE);
        desc = dmaengine_prep_slave_sg(channel, &this->data_sgl,
                                        1, DMA_DEV_TO_MEM,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-       if (!desc) {
-               pr_err("step 2 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [3] : submit the DMA */
        set_dma_type(this, DMA_FOR_READ_DATA);
                                        (struct scatterlist *)pio,
                                        ARRAY_SIZE(pio), DMA_TRANS_NONE,
                                        DMA_CTRL_ACK);
-       if (!desc) {
-               pr_err("step 2 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
+
        set_dma_type(this, DMA_FOR_WRITE_ECC_PAGE);
        return start_dma_with_bch_irq(this, desc);
 }
        desc = dmaengine_prep_slave_sg(channel,
                                (struct scatterlist *)pio, 2,
                                DMA_TRANS_NONE, 0);
-       if (!desc) {
-               pr_err("step 1 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [2] Enable the BCH block and read. */
        command_mode = BV_GPMI_CTRL0_COMMAND_MODE__READ;
                                        (struct scatterlist *)pio,
                                        ARRAY_SIZE(pio), DMA_TRANS_NONE,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-       if (!desc) {
-               pr_err("step 2 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [3] Disable the BCH block */
        command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY;
                                (struct scatterlist *)pio, 3,
                                DMA_TRANS_NONE,
                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-       if (!desc) {
-               pr_err("step 3 error\n");
-               return -1;
-       }
+       if (!desc)
+               return -EINVAL;
 
        /* [4] submit the DMA */
        set_dma_type(this, DMA_FOR_READ_ECC_PAGE);