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Commit 8cb28155 authored by Linus Walleij's avatar Linus Walleij Committed by Russell King
Browse files

ARM: 6632/3: mmci: stop using the blockend interrupts 



Implement a suggestion from Russell to drop the use of blockend
interrupts altogether and instead rely on the data counter.

Tested with error-free cards on U300, U8500 and RealView PB1176.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 1bae4ce2

drivers/mmc/host/mmci.c

+20 −78
Original line number Diff line number Diff line
@@ -46,10 +46,6 @@ static unsigned int fmax = 515633; 
 *	      is asserted (likewise for RX)

 * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY

 *		  is asserted (likewise for RX)

 * @broken_blockend: the MCI_DATABLOCKEND is broken on the hardware

 *		and will not work at all.

 * @broken_blockend_dma: the MCI_DATABLOCKEND is broken on the hardware when

 *		using DMA.

 * @sdio: variant supports SDIO

 * @st_clkdiv: true if using a ST-specific clock divider algorithm

 */
@@ -59,8 +55,6 @@ struct variant_data { 
	unsigned int		datalength_bits;

	unsigned int		fifosize;

	unsigned int		fifohalfsize;

	bool			broken_blockend;

	bool			broken_blockend_dma;

	bool			sdio;

	bool			st_clkdiv;

};
@@ -76,7 +70,6 @@ static struct variant_data variant_u300 = { 
	.fifohalfsize		= 8 * 4,

	.clkreg_enable		= 1 << 13, /* HWFCEN */

	.datalength_bits	= 16,

	.broken_blockend_dma	= true,

	.sdio			= true,

};
@@ -86,7 +79,6 @@ static struct variant_data variant_ux500 = { 
	.clkreg			= MCI_CLK_ENABLE,

	.clkreg_enable		= 1 << 14, /* HWFCEN */

	.datalength_bits	= 24,

	.broken_blockend	= true,

	.sdio			= true,

	.st_clkdiv		= true,

};
@@ -210,8 +202,6 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) 
	host->data = data;

	host->size = data->blksz * data->blocks;

	host->data_xfered = 0;

	host->blockend = false;

	host->dataend = false;



	mmci_init_sg(host, data);
@@ -288,21 +278,26 @@ static void 
mmci_data_irq(struct mmci_host *host, struct mmc_data *data,

	      unsigned int status)

{

	struct variant_data *variant = host->variant;



	/* First check for errors */

	if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {

		u32 remain, success;



		/* Calculate how far we are into the transfer */

		remain = readl(host->base + MMCIDATACNT) << 2;

		success = data->blksz * data->blocks - remain;



		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ (status %08x)\n", status);

		if (status & MCI_DATACRCFAIL)

		if (status & MCI_DATACRCFAIL) {

			/* Last block was not successful */

			host->data_xfered = ((success / data->blksz) - 1 * data->blksz);

			data->error = -EILSEQ;

		else if (status & MCI_DATATIMEOUT)

		} else if (status & MCI_DATATIMEOUT) {

			host->data_xfered = success;

			data->error = -ETIMEDOUT;

		else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN))

		} else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN)) {

			host->data_xfered = success;

			data->error = -EIO;



		/* Force-complete the transaction */

		host->blockend = true;

		host->dataend = true;

		}



		/*

		 * We hit an error condition.  Ensure that any data
@@ -321,61 +316,14 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, 
		}

	}



	/*

	 * On ARM variants in PIO mode, MCI_DATABLOCKEND

	 * is always sent first, and we increase the

	 * transfered number of bytes for that IRQ. Then

	 * MCI_DATAEND follows and we conclude the transaction.

	 *

	 * On the Ux500 single-IRQ variant MCI_DATABLOCKEND

	 * doesn't seem to immediately clear from the status,

	 * so we can't use it keep count when only one irq is

	 * used because the irq will hit for other reasons, and

	 * then the flag is still up. So we use the MCI_DATAEND

	 * IRQ at the end of the entire transfer because

	 * MCI_DATABLOCKEND is broken.

	 *

	 * In the U300, the IRQs can arrive out-of-order,

	 * e.g. MCI_DATABLOCKEND sometimes arrives after MCI_DATAEND,

	 * so for this case we use the flags "blockend" and

	 * "dataend" to make sure both IRQs have arrived before

	 * concluding the transaction. (This does not apply

	 * to the Ux500 which doesn't fire MCI_DATABLOCKEND

	 * at all.) In DMA mode it suffers from the same problem

	 * as the Ux500.

	 */

	if (status & MCI_DATABLOCKEND) {

		/*

		 * Just being a little over-cautious, we do not

		 * use this progressive update if the hardware blockend

		 * flag is unreliable: since it can stay high between

		 * IRQs it will corrupt the transfer counter.

		 */

		if (!variant->broken_blockend)

			host->data_xfered += data->blksz;

		host->blockend = true;

	}



	if (status & MCI_DATAEND)

		host->dataend = true;

	if (status & MCI_DATABLOCKEND)

		dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");



	/*

	 * On variants with broken blockend we shall only wait for dataend,

	 * on others we must sync with the blockend signal since they can

	 * appear out-of-order.

	 */

	if (host->dataend && (host->blockend || variant->broken_blockend)) {

	if (status & MCI_DATAEND) {

		mmci_stop_data(host);



		/* Reset these flags */

		host->blockend = false;

		host->dataend = false;



		/*

		 * Variants with broken blockend flags need to handle the

		 * end of the entire transfer here.

		 */

		if (variant->broken_blockend && !data->error)

		if (!data->error)

			/* The error clause is handled above, success! */

			host->data_xfered += data->blksz * data->blocks;



		if (!data->stop) {
@@ -770,7 +718,6 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) 
	struct variant_data *variant = id->data;

	struct mmci_host *host;

	struct mmc_host *mmc;

	unsigned int mask;

	int ret;



	/* must have platform data */
@@ -951,12 +898,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) 
			goto irq0_free;

	}



	mask = MCI_IRQENABLE;

	/* Don't use the datablockend flag if it's broken */

	if (variant->broken_blockend)

		mask &= ~MCI_DATABLOCKEND;



	writel(mask, host->base + MMCIMASK0);

	writel(MCI_IRQENABLE, host->base + MMCIMASK0);



	amba_set_drvdata(dev, mmc);

drivers/mmc/host/mmci.h

+1 −4
Original line number Diff line number Diff line
@@ -137,7 +137,7 @@ 
#define MCI_IRQENABLE	\

	(MCI_CMDCRCFAILMASK|MCI_DATACRCFAILMASK|MCI_CMDTIMEOUTMASK|	\

	MCI_DATATIMEOUTMASK|MCI_TXUNDERRUNMASK|MCI_RXOVERRUNMASK|	\

	MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_DATABLOCKENDMASK)

	MCI_CMDRESPENDMASK|MCI_CMDSENTMASK)



/* These interrupts are directed to IRQ1 when two IRQ lines are available */

#define MCI_IRQ1MASK \
@@ -177,9 +177,6 @@ struct mmci_host { 
	struct timer_list	timer;

	unsigned int		oldstat;



	bool			blockend;

	bool			dataend;



	/* pio stuff */

	struct sg_mapping_iter	sg_miter;

	unsigned int		size;