Hi Biju, Vinod,
On Thu, Sep 23, 2021 at 12:25 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> Currently, DMA clocks are turned on by the bootloader.
> This patch adds support for DMA clock handling so that
> the driver manages the DMA clocks.
>
> Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
If I'm not mistaken, this is a fix we want in v5.15, to avoid
regressions when the clock driver will be fixed (in clk-fixes for
v5.15), and DMA will be enabled in DT (in v5.16)?
Thanks!
> ---
> v1->v2:
> * Handled the failure case for pm_runtime_resume_and_get
> * Added Geert's Rb tag.
> ---
> drivers/dma/sh/rz-dmac.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
> index f9f30cbeccbe..d9f2cfef878e 100644
> --- a/drivers/dma/sh/rz-dmac.c
> +++ b/drivers/dma/sh/rz-dmac.c
> @@ -18,6 +18,7 @@
> #include <linux/of_dma.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/slab.h>
> #include <linux/spinlock.h>
>
> @@ -872,6 +873,13 @@ static int rz_dmac_probe(struct platform_device *pdev)
> /* Initialize the channels. */
> INIT_LIST_HEAD(&dmac->engine.channels);
>
> + pm_runtime_enable(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
> + goto err_pm_disable;
> + }
> +
> for (i = 0; i < dmac->n_channels; i++) {
> ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
> if (ret < 0)
> @@ -925,6 +933,10 @@ static int rz_dmac_probe(struct platform_device *pdev)
> channel->lmdesc.base_dma);
> }
>
> + pm_runtime_put(&pdev->dev);
> +err_pm_disable:
> + pm_runtime_disable(&pdev->dev);
> +
> return ret;
> }
>
> @@ -943,6 +955,8 @@ static int rz_dmac_remove(struct platform_device *pdev)
> }
> of_dma_controller_free(pdev->dev.of_node);
> dma_async_device_unregister(&dmac->engine);
> + pm_runtime_put(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
>
> return 0;
> }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
