On Wed, 2012-07-18 at 14:26 +0530, Laxman Dewangan wrote:
> Enable the DMA clock when registering DMA driver and
> disable clock when removing the DMA driver.
>
> The failure was observed on Tegra20 based system by
> Stephen Warren. However, it is working fine on tegra30
> based system and probably becasue uboot enable the clock
> on Tegra30.
Don't know much about the clock subsystem, but shouldn't the clocks be
enabled runtime..... when you actually start using the controller??
>
> Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
> Reported-by: Stephen Warren <swarren@xxxxxxxxxxxxx>
> ---
> drivers/dma/tegra20-apb-dma.c | 7 +++++++
> 1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index d52dbc6..ccfdaf4 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -1255,6 +1255,12 @@ static int __devinit tegra_dma_probe(struct platform_device *pdev)
> }
> }
>
> + ret = clk_prepare_enable(tdma->dma_clk);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret);
> + goto err_pm_disable;
> + }
> +
> /* Reset DMA controller */
> tegra_periph_reset_assert(tdma->dma_clk);
> udelay(2);
> @@ -1363,6 +1369,7 @@ static int __devexit tegra_dma_remove(struct platform_device *pdev)
> if (!pm_runtime_status_suspended(&pdev->dev))
> tegra_dma_runtime_suspend(&pdev->dev);
>
> + clk_disable_unprepare(tdma->dma_clk);
> return 0;
> }
>
--
~Vinod
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