From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@deeprootsystems.com (Kevin Hilman) Date: Wed, 10 Nov 2010 08:14:30 -0800 Subject: [PATCH v3 13/13] OMAP: PM: DMA: Enable runtime pm In-Reply-To: (Manjunath Kondaiah G.'s message of "Wed, 10 Nov 2010 19:32:19 +0530") References: <1288099513-1854-1-git-send-email-manjugk@ti.com> <1288099513-1854-14-git-send-email-manjugk@ti.com> <87fwvajepy.fsf@deeprootsystems.com> Message-ID: <871v6tdul5.fsf@deeprootsystems.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org "G, Manjunath Kondaiah" writes: >> "G, Manjunath Kondaiah" writes: >> >> > Enable runtime pm and use pm_runtime_get and pm_runtime_put >> > for OMAP DMA driver. >> > >> > Signed-off-by: G, Manjunath Kondaiah >> > Cc: Benoit Cousson >> > Cc: Kevin Hilman >> > Cc: Santosh Shilimkar >> > --- >> > arch/arm/plat-omap/dma.c | 13 +++++++++++++ >> > 1 files changed, 13 insertions(+), 0 deletions(-) >> > >> > diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c >> > index 41b14b0..feac7ee 100644 >> > --- a/arch/arm/plat-omap/dma.c >> > +++ b/arch/arm/plat-omap/dma.c >> > @@ -35,6 +35,7 @@ >> > #include >> > #include >> > #include >> > +#include >> > >> > #include >> > #include >> > @@ -367,6 +368,8 @@ int omap_request_dma(int dev_id, const >> char *dev_name, >> > chan = dma_chan + free_ch; >> > chan->dev_id = dev_id; >> > >> > + pm_runtime_get(&pd->dev); >> >> The _get() call is asynchronous. So if the device was actually >> idled/disabled, immediately after this call it may still be >> idle/disabled. When using the asynchronous versions of the API, the >> device should not be touched until the driver's ->runtime_resume() >> callback is called. > > driver runtime_resume will call omap_device_enable. How do we make > we check from driver side, whether omap_device_enable execution is complete > or not. It is complete when the driver's runtime_resume hook is called. The OMAP runtime PM core calls omap_device_enable() before calling the driver's callback. See arch/arm/mach-omap2/pm_bus.c for details. Alternatively, just use _get_sync() which doesn't return until the device is ready. Kevin