Commit 1791b13e authored by James Hogan's avatar James Hogan Committed by Chris Ball
Browse files

mmc: dw_mmc: convert card tasklet to workqueue 



Convert the card insert/remove tasklet to a workqueue, and call the
setpower platform specific callback without the spinlock held. This
means neither of the setpower or get_cd callbacks are called from atomic
context which allows them to sleep.

Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Acked-by: default avatarWill Newton <will.newton@imgtec.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 7456caae

drivers/mmc/host/dw_mmc.c

+31 −19
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/mmc/dw_mmc.h>

#include <linux/bitops.h>

#include <linux/regulator/consumer.h>

#include <linux/workqueue.h>



#include "dw_mmc.h"
@@ -100,6 +101,8 @@ struct dw_mci_slot { 
	int			last_detect_state;

};



static struct workqueue_struct *dw_mci_card_workqueue;



#if defined(CONFIG_DEBUG_FS)

static int dw_mci_req_show(struct seq_file *s, void *v)

{
@@ -1255,7 +1258,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) 


		if (pending & SDMMC_INT_CD) {

			mci_writel(host, RINTSTS, SDMMC_INT_CD);

			tasklet_schedule(&host->card_tasklet);

			queue_work(dw_mci_card_workqueue, &host->card_work);

		}



	} while (pass_count++ < 5);
@@ -1274,9 +1277,9 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static void dw_mci_tasklet_card(unsigned long data)

static void dw_mci_work_routine_card(struct work_struct *work)

{

	struct dw_mci *host = (struct dw_mci *)data;

	struct dw_mci *host = container_of(work, struct dw_mci, card_work);

	int i;



	for (i = 0; i < host->num_slots; i++) {
@@ -1288,22 +1291,21 @@ static void dw_mci_tasklet_card(unsigned long data) 


		present = dw_mci_get_cd(mmc);

		while (present != slot->last_detect_state) {

			spin_lock(&host->lock);



			dev_dbg(&slot->mmc->class_dev, "card %s\n",

				present ? "inserted" : "removed");



			/* Power up slot (before spin_lock, may sleep) */

			if (present != 0 && host->pdata->setpower)

				host->pdata->setpower(slot->id, mmc->ocr_avail);



			spin_lock_bh(&host->lock);



			/* Card change detected */

			slot->last_detect_state = present;



			/* Power up slot */

			if (present != 0) {

				if (host->pdata->setpower)

					host->pdata->setpower(slot->id,

							      mmc->ocr_avail);



			/* Mark card as present if applicable */

			if (present != 0)

				set_bit(DW_MMC_CARD_PRESENT, &slot->flags);

			}



			/* Clean up queue if present */

			mrq = slot->mrq;
@@ -1353,8 +1355,6 @@ static void dw_mci_tasklet_card(unsigned long data) 


			/* Power down slot */

			if (present == 0) {

				if (host->pdata->setpower)

					host->pdata->setpower(slot->id, 0);

				clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);



				/*
@@ -1376,7 +1376,12 @@ static void dw_mci_tasklet_card(unsigned long data) 


			}



			spin_unlock(&host->lock);

			spin_unlock_bh(&host->lock);



			/* Power down slot (after spin_unlock, may sleep) */

			if (present == 0 && host->pdata->setpower)

				host->pdata->setpower(slot->id, 0);



			present = dw_mci_get_cd(mmc);

		}
@@ -1476,7 +1481,7 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id) 
	 * Card may have been plugged in prior to boot so we

	 * need to run the detect tasklet

	 */

	tasklet_schedule(&host->card_tasklet);

	queue_work(dw_mci_card_workqueue, &host->card_work);



	return 0;

}
@@ -1665,12 +1670,15 @@ static int dw_mci_probe(struct platform_device *pdev) 
	mci_writel(host, CLKSRC, 0);



	tasklet_init(&host->tasklet, dw_mci_tasklet_func, (unsigned long)host);

	tasklet_init(&host->card_tasklet,

		     dw_mci_tasklet_card, (unsigned long)host);

	dw_mci_card_workqueue = alloc_workqueue("dw-mci-card",

			WQ_MEM_RECLAIM | WQ_NON_REENTRANT, 1);

	if (!dw_mci_card_workqueue)

		goto err_dmaunmap;

	INIT_WORK(&host->card_work, dw_mci_work_routine_card);



	ret = request_irq(irq, dw_mci_interrupt, 0, "dw-mci", host);

	if (ret)

		goto err_dmaunmap;

		goto err_workqueue;



	platform_set_drvdata(pdev, host);
@@ -1714,6 +1722,9 @@ err_init_slot: 
	}

	free_irq(irq, host);



err_workqueue:

	destroy_workqueue(dw_mci_card_workqueue);



err_dmaunmap:

	if (host->use_dma && host->dma_ops->exit)

		host->dma_ops->exit(host);
@@ -1753,6 +1764,7 @@ static int __exit dw_mci_remove(struct platform_device *pdev) 
	mci_writel(host, CLKSRC, 0);



	free_irq(platform_get_irq(pdev, 0), host);

	destroy_workqueue(dw_mci_card_workqueue);

	dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);



	if (host->use_dma && host->dma_ops->exit)

include/linux/mmc/dw_mmc.h

+1 −1
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ struct dw_mci { 
	u32			stop_cmdr;

	u32			dir_status;

	struct tasklet_struct	tasklet;

	struct tasklet_struct	card_tasklet;

	struct work_struct	card_work;

	unsigned long		pending_events;

	unsigned long		completed_events;

	enum dw_mci_state	state;

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