Re: [PATCH v6 3/5] remoteproc: Add support for runtime PM

Bjorn Andersson
2020-04-20T06:49:53Z

On Fri 17 Apr 10:00 PDT 2020, Paul Cercueil wrote:

> Call pm_runtime_get_sync() before the firmware is loaded, and
> pm_runtime_put() after the remote processor has been stopped.
>
> Even though the remoteproc device has no PM callbacks, this allows the
> parent device's PM callbacks to be properly called.
>
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
>
> Notes:
> v2-v4: No change
> v5: Move calls to prepare/unprepare to rproc_fw_boot/rproc_shutdown
> v6: Instead of prepare/unprepare callbacks, use PM runtime callbacks
>
> drivers/remoteproc/remoteproc_core.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index a7f96bc98406..d391b054efd8 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -29,6 +29,7 @@
> #include <linux/devcoredump.h>
> #include <linux/rculist.h>
> #include <linux/remoteproc.h>
> +#include <linux/pm_runtime.h>
> #include <linux/iommu.h>
> #include <linux/idr.h>
> #include <linux/elf.h>
> @@ -1384,6 +1385,8 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>
> dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
>
> + pm_runtime_get_sync(dev);

This can return an error, should we ignore this?

Apart from that this looks good.

Regards,
Bjorn

> +
> /*
> * if enabling an IOMMU isn't relevant for this rproc, this is
> * just a nop
> @@ -1391,7 +1394,7 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
> ret = rproc_enable_iommu(rproc);
> if (ret) {
> dev_err(dev, "can't enable iommu: %d\n", ret);
> - return ret;
> + goto put_pm_runtime;
> }
>
> rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
> @@ -1435,6 +1438,8 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
> rproc->table_ptr = NULL;
> disable_iommu:
> rproc_disable_iommu(rproc);
> +put_pm_runtime:
> + pm_runtime_put(dev);
> return ret;
> }
>
> @@ -1840,6 +1845,8 @@ void rproc_shutdown(struct rproc *rproc)
>
> rproc_disable_iommu(rproc);
>
> + pm_runtime_put(dev);
> +
> /* Free the copy of the resource table */
> kfree(rproc->cached_table);
> rproc->cached_table = NULL;
> @@ -2118,6 +2125,9 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
>
> rproc->state = RPROC_OFFLINE;
>
> + pm_runtime_no_callbacks(&rproc->dev);
> + pm_runtime_enable(&rproc->dev);
> +
> return rproc;
> }
> EXPORT_SYMBOL(rproc_alloc);
> @@ -2133,6 +2143,7 @@ EXPORT_SYMBOL(rproc_alloc);
> */
> void rproc_free(struct rproc *rproc)
> {
> + pm_runtime_disable(&rproc->dev);
> put_device(&rproc->dev);
> }
> EXPORT_SYMBOL(rproc_free);
> --
> 2.25.1
>