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Commit 18f92bc0 authored by Jerome Brunet's avatar Jerome Brunet Committed by Ulf Hansson
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mmc: meson-gx: make sure the descriptor is stopped on errors 



On errors, if we don't stop the descriptor chain, it may continue to
run and raise IRQ after we have called mmc_request_done(). This is bad
because we won't be able to get cmd anymore and properly deal with the
IRQ.

This patch makes sure the descriptor chain is stopped before
calling mmc_request_done()

Fixes: 79ed05e3 ("mmc: meson-gx: add support for descriptor chain mode")
Signed-off-by: default avatarJerome Brunet <jbrunet@baylibre.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 41fd4cae

drivers/mmc/host/meson-gx-mmc.c

+63 −10
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>
@@ -90,9 +91,11 @@ 
#define   CFG_CLK_ALWAYS_ON BIT(18)

#define   CFG_CHK_DS BIT(20)

#define   CFG_AUTO_CLK BIT(23)

#define   CFG_ERR_ABORT BIT(27)



#define SD_EMMC_STATUS 0x48

#define   STATUS_BUSY BIT(31)

#define   STATUS_DESC_BUSY BIT(30)

#define   STATUS_DATI GENMASK(23, 16)



#define SD_EMMC_IRQ_EN 0x4c
@@ -928,6 +931,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) 


	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);

	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */

	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */



	meson_mmc_set_response_bits(cmd, &cmd_cfg);
@@ -1022,6 +1026,17 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id) 
	u32 irq_en, status, raw_status;

	irqreturn_t ret = IRQ_NONE;



	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);

	raw_status = readl(host->regs + SD_EMMC_STATUS);

	status = raw_status & irq_en;



	if (!status) {

		dev_dbg(host->dev,

			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",

			 irq_en, raw_status);

		return IRQ_NONE;

	}



	if (WARN_ON(!host) || WARN_ON(!host->cmd))

		return IRQ_NONE;
@@ -1029,22 +1044,18 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id) 


	cmd = host->cmd;

	data = cmd->data;

	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);

	raw_status = readl(host->regs + SD_EMMC_STATUS);

	status = raw_status & irq_en;



	cmd->error = 0;

	if (status & IRQ_CRC_ERR) {

		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);

		cmd->error = -EILSEQ;

		ret = IRQ_HANDLED;

		ret = IRQ_WAKE_THREAD;

		goto out;

	}



	if (status & IRQ_TIMEOUTS) {

		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);

		cmd->error = -ETIMEDOUT;

		ret = IRQ_HANDLED;

		ret = IRQ_WAKE_THREAD;

		goto out;

	}
@@ -1069,17 +1080,49 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id) 
	/* ack all enabled interrupts */

	writel(irq_en, host->regs + SD_EMMC_STATUS);



	if (cmd->error) {

		/* Stop desc in case of errors */

		u32 start = readl(host->regs + SD_EMMC_START);



		start &= ~START_DESC_BUSY;

		writel(start, host->regs + SD_EMMC_START);

	}



	if (ret == IRQ_HANDLED)

		meson_mmc_request_done(host->mmc, cmd->mrq);

	else if (ret == IRQ_NONE)

		dev_warn(host->dev,

			 "Unexpected IRQ! status=0x%08x, irq_en=0x%08x\n",

			 raw_status, irq_en);



	spin_unlock(&host->lock);

	return ret;

}



static int meson_mmc_wait_desc_stop(struct meson_host *host)

{

	int loop;

	u32 status;



	/*

	 * It may sometimes take a while for it to actually halt. Here, we

	 * are giving it 5ms to comply

	 *

	 * If we don't confirm the descriptor is stopped, it might raise new

	 * IRQs after we have called mmc_request_done() which is bad.

	 */

	for (loop = 50; loop; loop--) {

		status = readl(host->regs + SD_EMMC_STATUS);

		if (status & (STATUS_BUSY | STATUS_DESC_BUSY))

			udelay(100);

		else

			break;

	}



	if (status & (STATUS_BUSY | STATUS_DESC_BUSY)) {

		dev_err(host->dev, "Timed out waiting for host to stop\n");

		return -ETIMEDOUT;

	}



	return 0;

}



static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)

{

	struct meson_host *host = dev_id;
@@ -1090,6 +1133,13 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id) 
	if (WARN_ON(!cmd))

		return IRQ_NONE;



	if (cmd->error) {

		meson_mmc_wait_desc_stop(host);

		meson_mmc_request_done(host->mmc, cmd->mrq);



		return IRQ_HANDLED;

	}



	data = cmd->data;

	if (meson_mmc_bounce_buf_read(data)) {

		xfer_bytes = data->blksz * data->blocks;
@@ -1130,6 +1180,9 @@ static void meson_mmc_cfg_init(struct meson_host *host) 
	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));

	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));



	/* abort chain on R/W errors */

	cfg |= CFG_ERR_ABORT;



	writel(cfg, host->regs + SD_EMMC_CFG);

}