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authorRobert Jarzmik2015-02-20 19:36:43 +0100
committerBrian Norris2015-02-28 01:08:36 -0800
commit24542257a3b987025d4b998ec2d15e556c98ad3f (patch)
tree5fa45c4488a75455dfb75d305ec688bb8bf07d51
parentadf716d2f3e62820cc86cdb08c277516c7012352 (diff)
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 <robert.jarzmik@free.fr> Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
-rw-r--r--drivers/mtd/nand/pxa3xx_nand.c22
1 files 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;