This patch moves the bulk transfer action outside of interrupt context, along with the STOP transmission action for multiblock transfers.
It's prompted by https://docs.openmoko.org/trac/ticket/2180 But it can impact throughput to SD card, so it's for testing currently. Signed-off-by: Andy Green <[email protected]> --- drivers/mfd/glamo/glamo-mci.c | 61 ++++++++++++++++++++++++++++++----------- drivers/mfd/glamo/glamo-mci.h | 3 +- 2 files changed, 46 insertions(+), 18 deletions(-) diff --git a/drivers/mfd/glamo/glamo-mci.c b/drivers/mfd/glamo/glamo-mci.c index e836913..bc3ed66 100644 --- a/drivers/mfd/glamo/glamo-mci.c +++ b/drivers/mfd/glamo/glamo-mci.c @@ -21,6 +21,7 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/spinlock.h> +#include <linux/workqueue.h> #include <asm/dma.h> #include <asm/dma-mapping.h> @@ -331,6 +332,35 @@ static int __glamo_mci_set_card_clock(struct glamo_mci_host *host, int freq, return real_rate; } + +static void glamo_mci_irq_worker(struct work_struct *work) +{ + struct glamo_mci_host *host = + container_of(work, struct glamo_mci_host, irq_work); + struct mmc_command *cmd = host->mrq->cmd; + + if (host->pio_active == XFER_READ) + do_pio_read(host); + + host->mrq->data->bytes_xfered = host->pio_count; + dev_dbg(&host->pdev->dev, "count=%d\n", host->pio_count); + + /* issue STOP if we have been given one to use */ + if (host->mrq->stop) { + host->cmd_is_stop = 1; + glamo_mci_send_request(host->mmc); + host->cmd_is_stop = 0; + } + + if (!sd_idleclk && !host->force_slow_during_powerup) + /* clock off */ + __glamo_mci_fix_card_div(host, -1); + + host->complete_what = COMPLETION_NONE; + host->mrq = NULL; + mmc_request_done(host->mmc, cmd->mrq); +} + static void glamo_mci_irq_host(struct glamo_mci_host *host) { u16 status; @@ -351,6 +381,7 @@ static void glamo_mci_irq_host(struct glamo_mci_host *host) spin_lock_irqsave(&host->complete_lock, iflags); status = readw(host->base + GLAMO_REG_MMC_RB_STAT1); + dev_dbg(&host->pdev->dev, "status = 0x%04x\n", status); /* ack this interrupt source */ writew(GLAMO_IRQ_MMC, @@ -371,32 +402,25 @@ static void glamo_mci_irq_host(struct glamo_mci_host *host) goto done; } - /* disable the initial slow start after first bulk transfer */ + /* + * disable the initial slow start after first bulk transfer + */ if (host->force_slow_during_powerup) host->force_slow_during_powerup--; - if (host->pio_active == XFER_READ) - do_pio_read(host); - - host->mrq->data->bytes_xfered = host->pio_count; - dev_dbg(&host->pdev->dev, "status = 0x%04x count=%d\n", - status, host->pio_count); - - /* issue STOP if we have been given one to use */ - if (host->mrq->stop) { - host->cmd_is_stop = 1; - glamo_mci_send_request(host->mmc); - host->cmd_is_stop = 0; - } + /* + * we perform the memcpy out of Glamo memory outside of IRQ context + * so we don't block other interrupts + */ + schedule_work(&host->irq_work); - if (!sd_idleclk && !host->force_slow_during_powerup) - /* clock off */ - __glamo_mci_fix_card_div(host, -1); + goto leave; done: host->complete_what = COMPLETION_NONE; host->mrq = NULL; mmc_request_done(host->mmc, cmd->mrq); +leave: spin_unlock_irqrestore(&host->complete_lock, iflags); } @@ -914,6 +938,7 @@ static int glamo_mci_probe(struct platform_device *pdev) host->pio_active = XFER_NONE; spin_lock_init(&host->complete_lock); + INIT_WORK(&host->irq_work, glamo_mci_irq_worker); host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!host->mem) { @@ -1061,6 +1086,8 @@ static int glamo_mci_suspend(struct platform_device *dev, pm_message_t state) struct glamo_mci_host *host = mmc_priv(mmc); int ret; + cancel_work_sync(&host->irq_work); + /* * possible workaround for SD corruption during suspend - resume * make sure the clock was running during suspend and consequently diff --git a/drivers/mfd/glamo/glamo-mci.h b/drivers/mfd/glamo/glamo-mci.h index bd62e9a..daae7a3 100644 --- a/drivers/mfd/glamo/glamo-mci.h +++ b/drivers/mfd/glamo/glamo-mci.h @@ -54,9 +54,10 @@ struct glamo_mci_host { struct mmc_request *mrq; int cmd_is_stop; + struct work_struct irq_work; spinlock_t complete_lock; - volatile enum glamo_mci_waitfor + volatile enum glamo_mci_waitfor complete_what; volatile int dma_complete;
