static irqreturn_t s3cmci_irq()

in host/s3cmci.c [600:799]

• 149 lines of code
• 32 McCabe index (conditional complexity)

static irqreturn_t s3cmci_irq(int irq, void *dev_id)
{
	struct s3cmci_host *host = dev_id;
	struct mmc_command *cmd;
	u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt, mci_imsk;
	u32 mci_cclear = 0, mci_dclear;
	unsigned long iflags;

	mci_dsta = readl(host->base + S3C2410_SDIDSTA);
	mci_imsk = readl(host->base + host->sdiimsk);

	if (mci_dsta & S3C2410_SDIDSTA_SDIOIRQDETECT) {
		if (mci_imsk & S3C2410_SDIIMSK_SDIOIRQ) {
			mci_dclear = S3C2410_SDIDSTA_SDIOIRQDETECT;
			writel(mci_dclear, host->base + S3C2410_SDIDSTA);

			mmc_signal_sdio_irq(host->mmc);
			return IRQ_HANDLED;
		}
	}

	spin_lock_irqsave(&host->complete_lock, iflags);

	mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
	mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
	mci_fsta = readl(host->base + S3C2410_SDIFSTA);
	mci_dclear = 0;

	if ((host->complete_what == COMPLETION_NONE) ||
	    (host->complete_what == COMPLETION_FINALIZE)) {
		host->status = "nothing to complete";
		clear_imask(host);
		goto irq_out;
	}

	if (!host->mrq) {
		host->status = "no active mrq";
		clear_imask(host);
		goto irq_out;
	}

	cmd = host->cmd_is_stop ? host->mrq->stop : host->mrq->cmd;

	if (!cmd) {
		host->status = "no active cmd";
		clear_imask(host);
		goto irq_out;
	}

	if (!s3cmci_host_usedma(host)) {
		if ((host->pio_active == XFER_WRITE) &&
		    (mci_fsta & S3C2410_SDIFSTA_TFDET)) {

			disable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
			tasklet_schedule(&host->pio_tasklet);
			host->status = "pio tx";
		}

		if ((host->pio_active == XFER_READ) &&
		    (mci_fsta & S3C2410_SDIFSTA_RFDET)) {

			disable_imask(host,
				      S3C2410_SDIIMSK_RXFIFOHALF |
				      S3C2410_SDIIMSK_RXFIFOLAST);

			tasklet_schedule(&host->pio_tasklet);
			host->status = "pio rx";
		}
	}

	if (mci_csta & S3C2410_SDICMDSTAT_CMDTIMEOUT) {
		dbg(host, dbg_err, "CMDSTAT: error CMDTIMEOUT\n");
		cmd->error = -ETIMEDOUT;
		host->status = "error: command timeout";
		goto fail_transfer;
	}

	if (mci_csta & S3C2410_SDICMDSTAT_CMDSENT) {
		if (host->complete_what == COMPLETION_CMDSENT) {
			host->status = "ok: command sent";
			goto close_transfer;
		}

		mci_cclear |= S3C2410_SDICMDSTAT_CMDSENT;
	}

	if (mci_csta & S3C2410_SDICMDSTAT_CRCFAIL) {
		if (cmd->flags & MMC_RSP_CRC) {
			if (host->mrq->cmd->flags & MMC_RSP_136) {
				dbg(host, dbg_irq,
				    "fixup: ignore CRC fail with long rsp\n");
			} else {
				/* note, we used to fail the transfer
				 * here, but it seems that this is just
				 * the hardware getting it wrong.
				 *
				 * cmd->error = -EILSEQ;
				 * host->status = "error: bad command crc";
				 * goto fail_transfer;
				*/
			}
		}

		mci_cclear |= S3C2410_SDICMDSTAT_CRCFAIL;
	}

	if (mci_csta & S3C2410_SDICMDSTAT_RSPFIN) {
		if (host->complete_what == COMPLETION_RSPFIN) {
			host->status = "ok: command response received";
			goto close_transfer;
		}

		if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
			host->complete_what = COMPLETION_XFERFINISH;

		mci_cclear |= S3C2410_SDICMDSTAT_RSPFIN;
	}

	/* errors handled after this point are only relevant
	   when a data transfer is in progress */

	if (!cmd->data)
		goto clear_status_bits;

	/* Check for FIFO failure */
	if (host->is2440) {
		if (mci_fsta & S3C2440_SDIFSTA_FIFOFAIL) {
			dbg(host, dbg_err, "FIFO failure\n");
			host->mrq->data->error = -EILSEQ;
			host->status = "error: 2440 fifo failure";
			goto fail_transfer;
		}
	} else {
		if (mci_dsta & S3C2410_SDIDSTA_FIFOFAIL) {
			dbg(host, dbg_err, "FIFO failure\n");
			cmd->data->error = -EILSEQ;
			host->status = "error:  fifo failure";
			goto fail_transfer;
		}
	}

	if (mci_dsta & S3C2410_SDIDSTA_RXCRCFAIL) {
		dbg(host, dbg_err, "bad data crc (outgoing)\n");
		cmd->data->error = -EILSEQ;
		host->status = "error: bad data crc (outgoing)";
		goto fail_transfer;
	}

	if (mci_dsta & S3C2410_SDIDSTA_CRCFAIL) {
		dbg(host, dbg_err, "bad data crc (incoming)\n");
		cmd->data->error = -EILSEQ;
		host->status = "error: bad data crc (incoming)";
		goto fail_transfer;
	}

	if (mci_dsta & S3C2410_SDIDSTA_DATATIMEOUT) {
		dbg(host, dbg_err, "data timeout\n");
		cmd->data->error = -ETIMEDOUT;
		host->status = "error: data timeout";
		goto fail_transfer;
	}

	if (mci_dsta & S3C2410_SDIDSTA_XFERFINISH) {
		if (host->complete_what == COMPLETION_XFERFINISH) {
			host->status = "ok: data transfer completed";
			goto close_transfer;
		}

		if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
			host->complete_what = COMPLETION_RSPFIN;

		mci_dclear |= S3C2410_SDIDSTA_XFERFINISH;
	}

clear_status_bits:
	writel(mci_cclear, host->base + S3C2410_SDICMDSTAT);
	writel(mci_dclear, host->base + S3C2410_SDIDSTA);

	goto irq_out;

fail_transfer:
	host->pio_active = XFER_NONE;

close_transfer:
	host->complete_what = COMPLETION_FINALIZE;

	clear_imask(host);
	tasklet_schedule(&host->pio_tasklet);

	goto irq_out;

irq_out:
	dbg(host, dbg_irq,
	    "csta:0x%08x dsta:0x%08x fsta:0x%08x dcnt:0x%08x status:%s.\n",
	    mci_csta, mci_dsta, mci_fsta, mci_dcnt, host->status);

	spin_unlock_irqrestore(&host->complete_lock, iflags);
	return IRQ_HANDLED;

}