From: Manjunath G Kondaiah <[email protected]> Enable runtime pm and use pm_runtime_get_sync and pm_runtime_put for OMAP DMA driver.
Since DMA driver callback will happen from interrupt context and DMA client driver will release all DMA resources from interrupt context itself, pm_runtime_put_sync() cannot be used in DMA driver. Instead, pm_runtime_put() is used which is asynchronous call and gets executed in work queue. Boot tested on OMAP4 blaze and all applicable tests are executed along with dma hwmod series. Signed-off-by: G, Manjunath Kondaiah <[email protected]> --- Discussion and alignment for using runtime API's in DMA can be accessed at: http://www.mail-archive.com/[email protected]/msg37819.html http://www.mail-archive.com/[email protected]/msg38355.html http://www.mail-archive.com/[email protected]/msg38391.html http://www.mail-archive.com/[email protected]/msg38400.html arch/arm/plat-omap/dma.c | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-) diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index c4b2b47..48ee292 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -35,6 +35,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/delay.h> +#include <linux/pm_runtime.h> #include <asm/system.h> #include <mach/hardware.h> @@ -58,6 +59,7 @@ enum { DMA_CHAIN_STARTED, DMA_CHAIN_NOTSTARTED }; #define OMAP_FUNC_MUX_ARM_BASE (0xfffe1000 + 0xec) static struct omap_system_dma_plat_info *p; +static struct platform_device *pd; static struct omap_dma_dev_attr *d; static int enable_1510_mode; @@ -676,6 +678,7 @@ int omap_request_dma(int dev_id, const char *dev_name, unsigned long flags; struct omap_dma_lch *chan; + pm_runtime_get_sync(&pd->dev); spin_lock_irqsave(&dma_chan_lock, flags); for (ch = 0; ch < dma_chan_count; ch++) { if (free_ch == -1 && dma_chan[ch].dev_id == -1) { @@ -686,6 +689,7 @@ int omap_request_dma(int dev_id, const char *dev_name, } if (free_ch == -1) { spin_unlock_irqrestore(&dma_chan_lock, flags); + pm_runtime_put(&pd->dev); return -EBUSY; } chan = dma_chan + free_ch; @@ -779,7 +783,7 @@ void omap_free_dma(int lch) p->dma_write(0, CCR, lch); omap_clear_dma(lch); } - + pm_runtime_put(&pd->dev); spin_lock_irqsave(&dma_chan_lock, flags); dma_chan[lch].dev_id = -1; dma_chan[lch].next_lch = -1; @@ -1979,6 +1983,7 @@ static int __devinit omap_system_dma_probe(struct platform_device *pdev) return -EINVAL; } + pd = pdev; d = p->dma_attr; errata = p->errata; @@ -2000,6 +2005,9 @@ static int __devinit omap_system_dma_probe(struct platform_device *pdev) } } + pm_runtime_enable(&pd->dev); + pm_runtime_get_sync(&pd->dev); + spin_lock_init(&dma_chan_lock); for (ch = 0; ch < dma_chan_count; ch++) { omap_clear_dma(ch); @@ -2065,6 +2073,14 @@ static int __devinit omap_system_dma_probe(struct platform_device *pdev) dma_chan[1].dev_id = 1; } p->show_dma_caps(); + + /* + * Note: If dma channels are reserved through boot paramters, + * then dma device is always enabled. + */ + if (!omap_dma_reserve_channels) + pm_runtime_put(&pd->dev); + return 0; exit_dma_irq_fail: -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
