On Fri, Apr 27, 2012 at 03:02:55PM +0800, Richard Zhao wrote:
> device_prep_dma_cyclic may be call in audio trigger function which is
> atomic context, so we make it atomic too.
>
> - change channel0 lock to spinlock.
> - Use polling to wait for channel0 finish running.
>
> Signed-off-by: Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Richard Zhao <richard.zhao@xxxxxxxxxxxxx>
> ---
> drivers/dma/imx-sdma.c | 57 +++++++++++++++++++++++++++--------------------
> 1 files changed, 33 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index fddccae..fc49ffa 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -24,7 +24,7 @@
> #include <linux/mm.h>
> #include <linux/interrupt.h>
> #include <linux/clk.h>
> -#include <linux/wait.h>
> +#include <linux/delay.h>
> #include <linux/sched.h>
> #include <linux/semaphore.h>
> #include <linux/spinlock.h>
> @@ -324,7 +324,7 @@ struct sdma_engine {
> struct dma_device dma_device;
> struct clk *clk_ipg;
> struct clk *clk_ahb;
> - struct mutex channel_0_lock;
> + spinlock_t channel_0_lock;
> struct sdma_script_start_addrs *script_addrs;
> };
>
> @@ -402,19 +402,31 @@ static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
> }
>
> /*
> - * sdma_run_channel - run a channel and wait till it's done
> + * sdma_run_channel0 - run a channel and wait till it's done
> */
> -static int sdma_run_channel(struct sdma_channel *sdmac)
> +static int sdma_run_channel0(struct sdma_channel *sdmac)
Renaming this to sdma_run_channel0 is fine, but then the argument should
be changed to struct sdma_engine. It makes no sense to say in the
function name that this function is channel 0 only and at the same time
allow to pass in an arbitrary other channel.
Sascha
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