From 24542257a3b987025d4b998ec2d15e556c98ad3f Mon Sep 17 00:00:00 2001 From: Robert Jarzmik Date: Fri, 20 Feb 2015 19:36:43 +0100 Subject: [PATCH] mtd: pxa3xx-nand: handle PIO in threaded interrupt Change the handling of the data stage in the driver : don't pump data in the top-half interrupt, but rather schedule a thread for non dma cases. This will enable latencies in the data pumping, especially if delays are required. Moreover platform shall be more reactive as other interrupts can be served while pumping data. No throughput degradation was observed, at least on the zylonite platform, while a slight degradation was being expected. Signed-off-by: Robert Jarzmik Tested-by: Maxime Ripard Signed-off-by: Brian Norris --- drivers/mtd/nand/pxa3xx_nand.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index bc677362bc73..3f09f2e9aeb4 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -605,11 +605,24 @@ static void start_data_dma(struct pxa3xx_nand_info *info) {} #endif +static irqreturn_t pxa3xx_nand_irq_thread(int irq, void *data) +{ + struct pxa3xx_nand_info *info = data; + + handle_data_pio(info); + + info->state = STATE_CMD_DONE; + nand_writel(info, NDSR, NDSR_WRDREQ | NDSR_RDDREQ); + + return IRQ_HANDLED; +} + static irqreturn_t pxa3xx_nand_irq(int irq, void *devid) { struct pxa3xx_nand_info *info = devid; unsigned int status, is_completed = 0, is_ready = 0; unsigned int ready, cmd_done; + irqreturn_t ret = IRQ_HANDLED; if (info->cs == 0) { ready = NDSR_FLASH_RDY; @@ -651,7 +664,8 @@ static irqreturn_t pxa3xx_nand_irq(int irq, void *devid) } else { info->state = (status & NDSR_RDDREQ) ? STATE_PIO_READING : STATE_PIO_WRITING; - handle_data_pio(info); + ret = IRQ_WAKE_THREAD; + goto NORMAL_IRQ_EXIT; } } if (status & cmd_done) { @@ -692,7 +706,7 @@ static irqreturn_t pxa3xx_nand_irq(int irq, void *devid) if (is_ready) complete(&info->dev_ready); NORMAL_IRQ_EXIT: - return IRQ_HANDLED; + return ret; } static inline int is_buf_blank(uint8_t *buf, size_t len) @@ -1708,7 +1722,9 @@ static int alloc_nand_resource(struct platform_device *pdev) /* initialize all interrupts to be disabled */ disable_int(info, NDSR_MASK); - ret = request_irq(irq, pxa3xx_nand_irq, 0, pdev->name, info); + ret = request_threaded_irq(irq, pxa3xx_nand_irq, + pxa3xx_nand_irq_thread, IRQF_ONESHOT, + pdev->name, info); if (ret < 0) { dev_err(&pdev->dev, "failed to request IRQ\n"); goto fail_free_buf; -- GitLab