static int h_msb_write_block()

in core/ms_block.c [473:579]

• 77 lines of code
• 18 McCabe index (conditional complexity)

static int h_msb_write_block(struct memstick_dev *card,
					struct memstick_request **out_mrq)
{
	struct msb_data *msb = memstick_get_drvdata(card);
	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
	struct scatterlist sg[2];
	u8 intreg, command;

	if (mrq->error)
		return msb_exit_state_machine(msb, mrq->error);

again:
	switch (msb->state) {

	/* HACK: Jmicon handling of TPCs between 8 and
	 *	sizeof(memstick_request.data) is broken due to hardware
	 *	bug in PIO mode that is used for these TPCs
	 *	Therefore split the write
	 */

	case MSB_WB_SEND_WRITE_PARAMS:
		if (!msb_write_regs(msb,
			offsetof(struct ms_register, param),
			sizeof(struct ms_param_register),
			&msb->regs.param))
			return 0;

		msb->state = MSB_WB_SEND_WRITE_OOB;
		return 0;

	case MSB_WB_SEND_WRITE_OOB:
		if (!msb_write_regs(msb,
			offsetof(struct ms_register, extra_data),
			sizeof(struct ms_extra_data_register),
			&msb->regs.extra_data))
			return 0;
		msb->state = MSB_WB_SEND_WRITE_COMMAND;
		return 0;


	case MSB_WB_SEND_WRITE_COMMAND:
		command = MS_CMD_BLOCK_WRITE;
		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
		msb->state = MSB_WB_SEND_INT_REQ;
		return 0;

	case MSB_WB_SEND_INT_REQ:
		msb->state = MSB_WB_RECEIVE_INT_REQ;
		if (msb_read_int_reg(msb, -1))
			return 0;
		fallthrough;

	case MSB_WB_RECEIVE_INT_REQ:
		intreg = mrq->data[0];
		msb->regs.status.interrupt = intreg;

		/* errors mean out of here, and fast... */
		if (intreg & (MEMSTICK_INT_CMDNAK))
			return msb_exit_state_machine(msb, -EIO);

		if (intreg & MEMSTICK_INT_ERR)
			return msb_exit_state_machine(msb, -EBADMSG);


		/* for last page we need to poll CED */
		if (msb->current_page == msb->pages_in_block) {
			if (intreg & MEMSTICK_INT_CED)
				return msb_exit_state_machine(msb, 0);
			msb->state = MSB_WB_SEND_INT_REQ;
			goto again;

		}

		/* for non-last page we need BREQ before writing next chunk */
		if (!(intreg & MEMSTICK_INT_BREQ)) {
			msb->state = MSB_WB_SEND_INT_REQ;
			goto again;
		}

		msb->int_polling = false;
		msb->state = MSB_WB_SEND_WRITE_DATA;
		fallthrough;

	case MSB_WB_SEND_WRITE_DATA:
		sg_init_table(sg, ARRAY_SIZE(sg));

		if (msb_sg_copy(msb->current_sg, sg, ARRAY_SIZE(sg),
			msb->current_sg_offset,
			msb->page_size) < msb->page_size)
			return msb_exit_state_machine(msb, -EIO);

		memstick_init_req_sg(mrq, MS_TPC_WRITE_LONG_DATA, sg);
		mrq->need_card_int = 1;
		msb->state = MSB_WB_RECEIVE_WRITE_CONFIRMATION;
		return 0;

	case MSB_WB_RECEIVE_WRITE_CONFIRMATION:
		msb->current_page++;
		msb->current_sg_offset += msb->page_size;
		msb->state = MSB_WB_SEND_INT_REQ;
		goto again;
	default:
		BUG();
	}

	return 0;
}