Commit b1a66593 authored by Ulf Hansson's avatar Ulf Hansson
Browse files

mmc: mmci: Add support for SW busy-end timeouts 



The ux500 variant doesn't have a HW based timeout to use for busy-end IRQs.
To avoid hanging and waiting for the card to stop signaling busy, let's
schedule a delayed work, according to the corresponding cmd->busy_timeout
for the command. If the work gets to run, let's kick the IRQ handler to
complete the currently running request/command.

Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20230620091113.33393-1-ulf.hansson@linaro.org
parent c467c8f0

drivers/mmc/host/mmci.c

+45 −5
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include <linux/pinctrl/consumer.h>

#include <linux/reset.h>

#include <linux/gpio/consumer.h>

#include <linux/workqueue.h>



#include <asm/div64.h>

#include <asm/io.h>
@@ -712,7 +713,8 @@ static void ux500_busy_clear_mask_done(struct mmci_host *host) 
 *                     |                 |

 *                    IRQ1              IRQ2

 */

static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)

static bool ux500_busy_complete(struct mmci_host *host, struct mmc_command *cmd,

				u32 status, u32 err_msk)

{

	void __iomem *base = host->base;

	int retries = 10;
@@ -756,6 +758,8 @@ static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk) 
				       host->variant->busy_detect_mask,

				       base + MMCIMASK0);

				host->busy_state = MMCI_BUSY_WAITING_FOR_START_IRQ;

				schedule_delayed_work(&host->ux500_busy_timeout_work,

				      msecs_to_jiffies(cmd->busy_timeout));

				goto out_ret_state;

			}

			retries--;
@@ -783,6 +787,7 @@ static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk) 
		} else {

			dev_dbg(mmc_dev(host->mmc),

				"lost busy status when waiting for busy start IRQ\n");

			cancel_delayed_work(&host->ux500_busy_timeout_work);

			ux500_busy_clear_mask_done(host);

		}

		break;
@@ -791,6 +796,7 @@ static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk) 
		if (!(status & host->variant->busy_detect_flag)) {

			host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);

			writel(host->variant->busy_detect_mask, base + MMCICLEAR);

			cancel_delayed_work(&host->ux500_busy_timeout_work);

			ux500_busy_clear_mask_done(host);

		} else {

			dev_dbg(mmc_dev(host->mmc),
@@ -1307,6 +1313,7 @@ static void 
mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)

{

	void __iomem *base = host->base;

	bool busy_resp = cmd->flags & MMC_RSP_BUSY;

	unsigned long long clks;



	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
@@ -1334,10 +1341,11 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c) 
	host->busy_status = 0;

	host->busy_state = MMCI_BUSY_DONE;



	if (host->variant->busy_timeout && cmd->flags & MMC_RSP_BUSY) {

		if (!cmd->busy_timeout)

	/* Assign a default timeout if the core does not provide one */

	if (busy_resp && !cmd->busy_timeout)

		cmd->busy_timeout = 10 * MSEC_PER_SEC;



	if (busy_resp && host->variant->busy_timeout) {

		if (cmd->busy_timeout > host->mmc->max_busy_timeout)

			clks = (unsigned long long)host->mmc->max_busy_timeout * host->cclk;

		else
@@ -1478,7 +1486,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, 


	/* Handle busy detection on DAT0 if the variant supports it. */

	if (busy_resp && host->variant->busy_detect)

		if (!host->ops->busy_complete(host, status, err_msk))

		if (!host->ops->busy_complete(host, cmd, status, err_msk))

			return;



	host->cmd = NULL;
@@ -1525,6 +1533,34 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, 
	}

}



/*

 * This busy timeout worker is used to "kick" the command IRQ if a

 * busy detect IRQ fails to appear in reasonable time. Only used on

 * variants with busy detection IRQ delivery.

 */

static void ux500_busy_timeout_work(struct work_struct *work)

{

	struct mmci_host *host = container_of(work, struct mmci_host,

					ux500_busy_timeout_work.work);

	unsigned long flags;

	u32 status;



	spin_lock_irqsave(&host->lock, flags);



	if (host->cmd) {

		dev_dbg(mmc_dev(host->mmc), "timeout waiting for busy IRQ\n");



		/* If we are still busy let's tag on a cmd-timeout error. */

		status = readl(host->base + MMCISTATUS);

		if (status & host->variant->busy_detect_flag)

			status |= MCI_CMDTIMEOUT;



		mmci_cmd_irq(host, host->cmd, status);

	}



	spin_unlock_irqrestore(&host->lock, flags);

}



static int mmci_get_rx_fifocnt(struct mmci_host *host, u32 status, int remain)

{

	return remain - (readl(host->base + MMCIFIFOCNT) << 2);
@@ -2339,6 +2375,10 @@ static int mmci_probe(struct amba_device *dev, 
			goto clk_disable;

	}



	if (host->variant->busy_detect)

		INIT_DELAYED_WORK(&host->ux500_busy_timeout_work,

				  ux500_busy_timeout_work);



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



	amba_set_drvdata(dev, mmc);

drivers/mmc/host/mmci.h

+2 −1
Original line number Diff line number Diff line
@@ -397,7 +397,7 @@ struct mmci_host_ops { 
	void (*dma_error)(struct mmci_host *host);

	void (*set_clkreg)(struct mmci_host *host, unsigned int desired);

	void (*set_pwrreg)(struct mmci_host *host, unsigned int pwr);

	bool (*busy_complete)(struct mmci_host *host, u32 status, u32 err_msk);

	bool (*busy_complete)(struct mmci_host *host, struct mmc_command *cmd, u32 status, u32 err_msk);

	void (*pre_sig_volt_switch)(struct mmci_host *host);

	int (*post_sig_volt_switch)(struct mmci_host *host, struct mmc_ios *ios);

};
@@ -455,6 +455,7 @@ struct mmci_host { 
	void			*dma_priv;



	s32			next_cookie;

	struct delayed_work	ux500_busy_timeout_work;

};



#define dma_inprogress(host)	((host)->dma_in_progress)

drivers/mmc/host/mmci_stm32_sdmmc.c

+2 −1
Original line number Diff line number Diff line
@@ -411,7 +411,8 @@ static u32 sdmmc_get_dctrl_cfg(struct mmci_host *host) 
	return datactrl;

}



static bool sdmmc_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)

static bool sdmmc_busy_complete(struct mmci_host *host, struct mmc_command *cmd,

				u32 status, u32 err_msk)

{

	void __iomem *base = host->base;

	u32 busy_d0, busy_d0end, mask, sdmmc_status;