From 1791b13ea4d97a6a7c162edd54485e932ad92f1b Mon Sep 17 00:00:00 2001 From: James Hogan Date: Fri, 24 Jun 2011 13:55:55 +0100 Subject: [PATCH] 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: James Hogan Acked-by: Will Newton Signed-off-by: Chris Ball --- drivers/mmc/host/dw_mmc.c | 50 +++++++++++++++++++++++--------------- include/linux/mmc/dw_mmc.h | 2 +- 2 files changed, 32 insertions(+), 20 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index c4bddf6a5f1f..3f610d55f38e 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -33,6 +33,7 @@ #include #include #include +#include #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) diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index 55d9909c7abd..dea48475c436 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -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; -- 2.20.1